Although the main cause may be attributed to a mechanical failure (if the theory is valid, that is) , I don't think over aggressiveness can be ruled out as an important background that ulitmately led to his death - especially, since this is McGuire we're talking about.
Therefore, I'd say that tactical misjudgement did play some part in his death. Would McGuire have had enough time to try and bail were he not so aggressive in his last encounter? I think so.
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Overconfidence, impetuousness, and dangerously high preference towards dogfighting that directly contradicts the general tactical recommendations against fighting better maneuvering planes, is all a death factor that claimed innumerable many young pilots - much more than 'aces' have been born out of them. Landing 14-round HO shots to the cockpit to kill the pilot is something that works for people like Marseilles, but would never amount up to much as a standard tactic. The same with 'flapfest' dogfighting.
In the particular fight that is the subject of this hijack, McGuire was trying hard, not just to score but to clear his own wingman, Weaver. Now, was it an aggressive decision for McGuire to call that drop tanks shouldn't be dropped, earlier in the fight? Yes. Was it out of line, considering McGuire knew he had three other good pilots with him against a single plane? It may or may not have been. For years, no one, including Weaver and Thropp, who were there, even knew of a second enemy plane being involved. So holding tanks when you have the odds in your favor 4 to 1 might be questionable, but you can see that given what they knew of the situation, it may not have seemed out of line.
That is not to say that McGuire was not very aggressive, possibly to a fault, he may well have been, more cautious pilots thought he was. McGuire stated not long before he died that he feared his luck could be running out. He felt he could not go home of his own will, he felt that he should wait until he was ordered to go home in no uncertain terms. And he knew the only way for that to happen was to equal or exceed Bong's score. The only way to do that was to fly and to score, as he also felt he could not order others to fly while he sat safely behind a desk.
McGuire's death, like most other things of that nature, can be attributed not to any one thing, but a series of circumstances that, had any one of those circumstances been altered even slightly, an entirely different outcome would have been very likely. Did McGuire contribute to his own death? Quite possibly. Was it entirely due to his flying style and tactics? Probably not.