If a founder as successful Zsu came in extremely drunk one time, yeah, I think extend him some grace. He fucked up - once. That's ok!
Did he kill someone? No. Did he lose a major customer account? No. Did he fire a top employee in a drunken rage? No.
He's under a lot of pressure and fucked up in an embarrassing way once. That doesn't mean he has a substance problem. It means he had a bad day.
If it happens a second time? Yeah, ok, now it's starting to be a track record. Third? Nuke him.
It's ok for people to fuck up sometimes