Doesn't look like the top guy was targeting the knee to me. It does look like the other wrestler lost his cool and was throwing borderline punches, but I do not believe it was enough for DQ. The only thing I can think of is that the official already warned them as he did appear to talk to both wrestlers earlier in the match. Either way if he is a 2xer he needs to be able to control his emotions, as others are going to do what they can to beat him.