In that instance, it was a case of subjective misinterpretation of the laws. This case is different. It's a complete lack of knowledge of the laws on behalf of the ref. The result should still stand but mistakes like this should not happen.
Equating the NFL with rugby is an even sillier argument than the previous. Even if they were somehow equatable, I've still never seen someone jump for the ball, get clipped, do a somersault and score. »
You have to consider consequence and action. Imagine a situation where someone takes a swing and misses completely. Is that as bad as a punch that connects? Clearly not. Should it still be punished to some degree? Clearly. A balance has to be struck between the two.