In that case, we can quite easily conclude this debate by saying that "reasonable force" is far too ambiguous to put a label on. There's also the fact that if you were to give someone a punch, it would be extremely difficult for the judge to rule whether it was reasonable or not, as they weren't aware of the situation. There's also the added complication that either party could lie, too.
In reply to your latter question: it depends on the individual as to what "they like" is. Some would throw them a punch, others would "politely ask them to leave". So yes, I do think it can fall under the category of reasonable force.

