The best way for men to counter this in a toxic environment is to call it out when they see it. This sends a message that being outwardly dehumanizing and dismissive is not okay, and is not the accepted norm.
Not saying it's still not the right thing to do, just, you should put yourselves in their shoes. Probably that entire room could have told the guy in unison "that wasn't cool" and they would have all been instantly fired, so, not sure what that's gonna do for anyone...
I suppose I could have stayed, but I also figured my colleague could stand up for himself. He's not a pushover.