Example, you are an Islamaphobe and you attack a woman wearing a head scarf, ripping it off because you think it is a hijab.
Lo and behold, the victim is a woman with alopecia and isn’t Muslim.
You are still guilty of an islamaphobic hate crime, because you perceived her as Muslim and your intent was to attack a woman for being a Muslim.
Hate crimes are always based on the victim being perceived as or passing as a vulnerable group.
If the person isn’t perceived as or passing as a member of the vulnerable group, then that type of hate crime cannot be applied.