Most likely this person has latched onto others before, so the group may already be well aware of his "pattern." I've had a few people do this to me as well, and it's truly miserable. I've found the best thing to do is to decide what I AM willing to do (if anything) and simply tell that person. When they object, just say "I'm sorry." When they object again, repeat "I'm sorry." etc. etc.....keep repeating it politely, just don't back down or get involved in their arguments. You need to put your emotional/mental health first in sobriety.
Just my opinion. Good luck!!!!!!