[18hrs]

I agree about the need to clearly register disagreement, but I'd opt for slightly less shock... I'd say, calmly and sternly "that is entirely inappropriate." I'd then call on others in the group to register their disagreement.

[fudged71]

A general statement like that can be argued.

"What you just said disgusts me" seems more fitting. You're communicating how it is personally affecting you. That can't be argued.