Good Discipline???

I have been uncomfortable with a behavior I have observed by cooperating teacher. Overall, I feel he is good with the students. But, there are times when he seems to have no patience (which I understand) and sends a student into the hall (which I don't understand). It seems he sends the students because they are disrupting the class and continue talking after being told to stop. However, from the 4 or 5 times I've seen this - I have not noticed the student being overly disruptive. But, I am not in the front of the class so I am sure there are things going on that I can't see. Regardless of how disruptive the student may be, it seems to me sending a student into the hall is not the correct "answer". Given our discussion in classroom management last week, I am even more certain that is not how the situation should be handled. I honestly cannot say how I would react to the situation. It is one of my concerns and I am not sure I feel we have been given a lot of tools to utilize. We are told to 'prevent' disruptive behavior by presenting meaningful and engaging lessons - but that is not full proof. I do not feel entirely comfortable judging a teacher who has so much experience, but this happens to be one area I question.