After standing by and keeping my tongue behind my teeth (keyboardwise)(and it is a hard exercise for me, far harder than a simulated PFL at my home field) I must say I feel some sympathy with the o/p. The Harvard's behaviour, as described (we haven't heard or seen the other party's version) was indeed inacceptable. Whether he was flying a warbird or a weight-shift microlight or a wide-body is irrelevant. As a matter of fact, whatever was said on the radio is just as irrelevant, the place being OCAS. Either plane, or even both, might well have been NORDO, and that would not have changed the least comma to the rules or responsabilities for either pilot, nor for the radio operator.
Before lining up, one checks for planes on final or even in the base leg, and judges whether line-up AND the associated take-off can be effected in a sufficiently safe manner. If not, hold short. That's law,
AFAIK, and it obviously wasn't respected.
That said, I can't help feeling the o/p is, at heart, taking the incident for what it was; as some have suggested he should. With his reported experience, he must know that **** happens, and he must have committed some less-than-perfect maneuvers himself. The opening post sounded rather objective. Only later, when apparently few would sympathise, did the tone get bitter. O/P seems to mainly regret that many write as if the Harvard's behaviour was perfectly normal and acceptable - and that is what it certainly wasn't.
PS My sincere apologies to any person concerned who is not a HE - I avoided (s)he and her/him purely for the sake of readability.