Prove it. It is impossible to show. It's also convenient. After all if you can claim that anyone who changes their mind was never really gay then you don't have to admit it can be a behavior choice. Yet last I checked anyone who indulged in homosexual behavior is considered homosexual.
I guess if an alcoholic manages to go dry then he was never a "real" alcoholic either. Eh? And all those people who binged on alcohol every weekend because they thought it was cool never really drank anything? Either way the results the same.
Opinion Miroku, it's all opinion