“But he does good work.”
Some possibly useful advice: if I'm at a conference and someone I sort of know says, "This one speaker is being an ass.  He's pestering me about another speaker."  I'm like, "yeah, yeah that's part of being an organizer".But if that person says, "Can you help me?  Bill Smith is harassing me."  Now they've got my attention.In this case I don't know what the exact dialog was, but if you want help be sure to ask for it and state clearly why.  People will respond more proactively.