You might argue that red did not satisfy 44.2 by not initially getting sufficiently clear of other boats in the first place.   Aside from that, if I found that red did the second turn as "prompty" as possible (no additional delay) after getting clear of the starboard tack boat that tacked, then I would be ok with those turns.  From the diagram, It seems like red sailed too far from green to satisfy "promptly".   As for 23, green is surely on her proper course, so 23 does not apply.

Red was clear until green forced the issue.  If a boat must move away to maintain her obligation to keep clear, I feel that such should be accepted.  Further red did not obtain any significant advantage by delaying her second turn

There is a Q&A (2021-006) that agrees with you, but I disagree with your assertion that red got no advantage from her delay. She got her momentum back, and the ability to make her second turn far faster.

The comments seem to indicate how subjective the application of the sailing rules can be at times.

Rule 23.2 says, "If reasonably possible, a boat shall not interfere with a boat that is taking a penalty, sailing on another leg or subject to rule 21.1 (ED: returning to start). However, after the starting signal this rule does not apply when the boat is sailing her roper course."
In addition, when Green altered course by tacking, she was obligated to give Red room to keep clear under rule 16.1. Red continued on port to keep clear and then resumed taking her penalty.
1. It is possible that Green broke rule 23.2 by tacking and thereby preventing Red from promptly completing her second turn. Was tacking like that Green's proper course?
2. If Green did not break rule 23.2, then Red met her obligation to keep clear of Green and then promptly resumed her circling penalty.
Either way, I would not penalize Red.
Rule 23.2 says nothing about what Red should do if she is interfered with. Of course, she can protest Green, but she must still complete her penalty for the original infringement. My inclination would be not to further penalize Red. I believe that she completed her two turns as promptly as she could, recognizing Green's actions.

The RYA have a case that covers this:
RYA 2015/1
Rule 44.2, One-Turn and Two-Turn Penalties
For a boat to properly take a turns penalty she must comply with the two requirements of rule 44.2: to get well clear of other boats as soon as possible; and, to promptly make the required number of turns.
SUMMARY OF THE FACTS
Daring was rounding a port-hand windward mark on starboard tack when she touched the mark. She wished to take a penalty and sailed past the mark and to windward of the course to the next mark. She bore away and gybed and then found her intended course was blocked by a number of boats, including Hot Rats, which had rounded the mark behind her and were sailing to the next mark. Daring sailed back towards the mark on port, allowing the other boats to pass her and then tacked to finish taking her turn.
Hot Rats protested Daring for hitting the mark and not properly taking a penalty. The protest committee found that Daring had not taken a One-Turn Penalty in compliance with rule 44.2 and disqualified her for breaking rule 31. Daring appealed on the grounds that the course that she actually sailed was equivalent to the disadvantage that she would have suffered in taking a One-Turn Penalty.
DECISION
The appeal is dismissed.
The requirements in rule 44.2 are absolute and cannot be satisfied by actions that may be equivalent, in time or distance.
The first requirement is to get well clear of other boats as soon after the incident as possible. If a boat commences her penalty turn from a position where the predictable course of other boats means that she would have to interrupt the turn, then she has failed to sail well clear as required by the rule.
The second requirement is to promptly make the required number of turns in the same direction, each turn including one tack and one gybe.
Daring did not sail sufficiently far from the fleet in order to take her turn as evidenced by the fact that other boats, who were sailing an entirely predictable course, interrupted the taking of her turn. Therefore, Daring was not well clear of other boats, did not take a One-Turn Penalty and was correctly disqualified for breaking rule 31.

The first requirement of rule 44.2 states " After getting well clear of other boats....." . Red fails to do this- therefore cannot claim protection of 44.2.

RE Jack Fenwick: I don't believe that this is equivalent to RYA 2015/1. Red was "well clear" of Green when she began her two-turn penalty. It was Green's alteration of course that altered that condition, which is what places her (Green) in jeopardy of being penalized under rule 23.2. It was certainly "reasonably possible" for Green not to have interfered with Red's penalty. In RYA 2015/1, the proper course for Rats was to steer for the next mark and Daring should have anticipated that Rats would alter course for the next mark as soon as she could do so when considering her possible obligations to the other boats rounding near her. This is not the case here as there is no mark nearby.
As a matter of safety, Red looks around, sees that she is "well clear" of Green, and commences her two-turn penalty by turning away from Green. At that point, most sailors are concentrating on the safe execution of the penalty as quickly as possible and not on watching for possible course changes by a boat that was on a course to pass some distance from the circles she was sailing. Green's tack caused her to interfere with Red.
RE Simon Zuchowicz: As above, Red was "well clear" of Green when she began her two-turn penalty and should not have to anticipate that Green may infringe rule 23.2.

Simon, the rule says a boat takes their penalty “after getting well clear” this is different to the definition “keep clear” I have no issue that this boat was well clear when she started her turn and so this part of the rule is met because it applies before the turn starts because of the tense used in the Rule and therefor is a condition that is met (or not) before the turn starts and doesn’t apply while taking the turn, 21.2 takes over at that point. 
Clark, I happen to have been on the jury this case is based on so I am happy to see the similarities. While our case involved a one turn penalty and this one a two turn penalty, we felt that by stopping the turn to sail straight (for whatever reason) meant the turn had stopped and therefore didn’t comply with the wording of the rule. In this case, the rule requires that two turns are done (which they are) in the same direction (which they are) but that they be done promptly, my interpretation is that by sailing straight for what looks to be three hull lengths, she has failed to comply with this part of the rule. 
Yes, it is strict but as promptly is not defined or in terminology it must be interpreted in the sense ordinarily understood in nautical or general use and a quick google search shows promptly defined as “with little or no delay; immediately” I can’t consider sailing three hull lengths (without more facts on boat type, speed, conditions etc.) as a little delay and therefore the turns were not prompt. 

Jack: I see your point about the three boat lengths, but what if Red had only sailed as far as she needed to keep clear of Green (her obligation as a port tack boat) and then immediately turned again in the same direction? Also, Green's tack, after Red had begun her two-turn penalty, looks like interference to me, absent a lay line or obstruction immediately in Green's path.
Finally, as a race official (either as part of the race committee or an on-the-water Judge, I would not have protested Red, assuming that this is a fleet race.
If I were Green, I would hesitate to protest Red for fear of being found to have broken rule 23.2.

I don’t know of many people who would protest for not doing turns properly but this is hypothetical. Without more facts, it is impossible to know if three lengths is prompt or not, the diagram appears to show both boats covering roughly the same net distance between pos 1 & 2 but red also manages to complete a tack and a gybe at the same time suggesting she is significantly quicker than green. It also suggests that she could have replicated the same turn and if she had then she would have been clear ahead after tacking and moving out of the way by turning in to the gybe and therefore have kept clear. Granted, the purpose of the diagram and question is to ask a question about the rules but if this was the diagram in facts found then for me, there was nothing to prevent the turns happening in the same place and they are not prompt. 
23.2 (assuming this is after the start) only applies if not sailing a proper course. Given a beat to windward can be sailed on either tack you would be hard pressed to prove it wasn’t a proper course without proving intent and if you can prove intent to interfere then you would likely be looking at rule 2 rather than 23.1 as at a minimum it is a deliberate breach of a rule. 

Jack, I believe that you and I are entering into a state of "violent agreement" regarding this hypothetical.
I believe that rule 23.2 provides some protection for Red and that a Protest Committee should give her some consideration in the case that she initially had adequate room to perform her penalty until Green tacked. In that respect this is significantly different with RYA 2015/1 (which I totally agree with).

I think it depends on quite how accurate we think the drawing is.  One could argue that green at position 2 would tack thinking red would be doing a second circle on top of the first and so she would be clear to windward (if she sheeted in sails and pointed up!)- why is red sailing on up the course at 2?  In my view red was initially clear; green has a right to tack, gives red enough room to avoid her, red does avoid her.  Then red sails a bit too far on up the course before doing the second turn.  Red would have been better to start her second turn immediately after she was clear of green.  As it is shown. I'd penalise red.  If it had been only a boatlength or so to clear green, then I'd not.  If red had continued to do her turn in the same place, i.e. not sailed a bit up the course, I have said green was in danger of interfering with a boat taking a penalty.....

My view is that at P1, Red to windward and with no boats in her path was clear and was able to start her penalty turns as required by R 44.2. There was no reason for her to anticipate that Green would tack as she was in mid-turn. It was when Green tacked to stbd, that Red’s ability to make her second turn promptly to comply with R44.2 was disrupted. 

Green can see that Red is taking a penalty turn just to windward, and there was no valid reason for Green to tack and thereby interfere with Red’s penalty turns which were already in progress and Green breaks R23.2 and should be penalised.

Red then went on to complete her second turn as soon as she was well clear of Green.

My thought is that the real issue is what to do about Red?  "Has Red complied with R 44.2?" 

My question is “May Red be exonerated under 43.1(a) for not complying exactly with the requirements of R 44 as her action to delay was compelled by Green breaking a rule”?

Is it valid to apply apply R43 to exonerate Red – as one does not break R 44.2 – R44.2 describes a procedure, and one either complies with the required action or not. But I think it would be harsh to either 
a) expect Red to start two turns all over, or worse,
b)  DSQ Red for the original event on the grounds that she did not comply with R 44.2 and therefore did not take a penalty.

John