Just vote-kick them and pray that you don't have any SJW/white knight in party that will vote no or worse make a fuss about it.
Anything else will either be a waste of your breath or earn you a warning/ban from the trigger-happy GM's.

Other than that we can just wait for SE to realize how silly and pointless their "don't talk about parsers" rule is, so we can state that someone doing bad in party and back up by solid data.