I didn't think it was such a big evil.
I mean...I burn people's faces off all the time, many of which don't really pose a serious threat to myself or the party, but they are enemy combatants, so flame on!
If I burn off a bad guys face off, is that automatically a good act? If so, I have a whole bucket full of credits I can use to kill little old ladies without fear of being evil...I don't necessarily want to be a good guy, but I don't really want to be evil either.
I don't know if this lady is evil, she could be an assassin trying to give me a disease, or a spy trying to turn the town against me by inciting me to violence...she was leading a small mob. (Also the character is a human teenager, so that's where a lot of this comes from.)