I think the main thing here is to be realistic and reasonable about the intent of the "offender" and the actual power behind the punch. It is clear to see that the punch Dirrel threw late was both unintentional and more of a love tap which would never have resulted in any significant damage to the opponent. Also it was sort of a straight on jab. On the other hand, Abraham, who is known to have a good punch, got Dirrel with a much harder punch thrown with more aggression and from an awkward angle that would twist the head more. The two are only similar in basic concept but otherwise, as someone said earlier, its like apples and oranges.