Absolutely a threat... assuming it was real. If the doc is really this big martial artist, why was the other guy not eating pavement? I think I would have responded if someone pulled a blade on me. Drunk or not, it was a threat.
Dr. Rey is a moron and it looks like he has been writing himself scripts for hormone therapy. Was he wearing his wife's shirt? I think homeboy just wanted to help the Dr. with a haircut.
Threat - yes.
Instigated - yes.
Reaction - WAY different than how I would've reacted to the loser whipping out his knife and making idle threats.
Simply, I don't think the Dr. felt threatened by the display of the knife although he seemed a little surprised at the "heckler's" response to being called out. Maybe the Doc was a little gun-shy since the lights and camera were on him while this all happened.
IMO - if you're gonna whip that itty-bitty blade out in response to getting called out, you better be prepared to eat it.
My feelings teeter on the edge of feeling justified in eliminating a threat like that with deadly force. Now if he would've made the slightest move or aggressive gesture?
Looks like a threat to me. But since the doctor instigated it and then verbally escalated the situation, I think he would have had a tough time proving self defense if he had gone hands on at that point.