Definitely take the high road. To do otherwise might foster a toxic working atmosphere. I mean, you are already starting with one jerk, you don't need two. Plus

Definitely take the high road. To do otherwise might foster a toxic working atmosphere. I mean, you are already starting with one jerk, you don't need two. Plus, he wasn't actually rude to YOU, and anyone who saw you being rude to him might think you were at fault without context. You could pull him up - "Hey, you were a bit of a dick with that interviewee, what's up?" Or flag it up to your boss that your colleague uses interviews as a bit of a power trip.