The "hostility" I referred to was the one towards the users. Basically, he's demanding users to show evidence that whatever they want is better than BM25. That

The "hostility" I referred to was the one towards the users. Basically, he's demanding users to show evidence that whatever they want is better than BM25. That's just wrong. Period. This is the reason I mention his job, because his job requires him to listen to the users, instead of taking something he learned in school and use that to talk condescendingly to his users. That's not gonna fly. Given this context, I think whatever I said it is entirely appropriate.