If I had a dollar for every "girl" I brought home who was was boy, I'd be rich.
Some were my own fault for not checking myself and others were from 'reputable' breeders who fell asleep at the wheel.
I just traded my own Lola and Ivy for a "female" sub-adult Albino Kahl Boa on the condition/promise the guy was keeping them both for himself and not only did he trade them away almost immediately to who-knows-where, the Boa is a boy.
I'm still grieving that I don't know where my girls went.
Trying to decide if filing a BOI on him will do any good.