@dappled_leaves Everything gets someone hot under the collar. I really can’t get worked up about it unless I have reason to think their objection is justified. If someone has been exclusively homosexual their entire life and then sees one person of the opposite sex who pings on their attraction radar, I’m not going to immediately reclassify them as bisexual if the experience doesn’t make them reclassify themselves that way.
Dan Savage sometimes tells the story of the lesbian firefighter who pinged on his radar once upon a time. Granted, he says she was rather mannish. But she was definitely a woman. Should I now doubt his self-identification as gay because of a single attraction that never led to anything?
As for bisexual erasure, the problem arises when people try to hide the existence of bisexuality (such as by denying it exists or by forcing bisexuals into other categories). But if the person you aren’t calling bisexual isn’t bisexual, then it can hardly be bisexual erasure. Nothing about “this person isn’t bisexual” entails “nobody is bisexual” or “bisexuality isn’t real,” so it only counts as bisexual erasure if the person is actually bisexual (or at least identifies that way).
As for the stigma, I also have no idea why it exists. Though I do understand why it causes some bisexuals to be hesitant to come out, despite that being one of the most useful things they can do to fight the stigma.