I would say that grabbing the leader is pretty much the same principle.

In your circumstance you are trying to avoid escalating a situation that has not gotten out of control yet!

Even if it does, as security, you have different responsibilities!

The problem with a mob is that because you are surrounded there willl always be a blind side unless you can break the circle. Because of your blind side you are constantly in a vulnerable position, you may not have time to piddle around being nice. The longer you piddle the longer you are vulnerable.