I watched the whole video. The clerk in the store didn’t seem nervous or clumsy to me. He seemed to be enjoying himself. I realize it’s all a matter of perspective, but what I saw was a trans woman being bullied, quite deliberately. Should she have lost her temper?
I don’t know. Clearly she did lose her temper after prolonged provocation. I think the clerk got the reaction he was looking for.
That’s what bullies do.