This has been one of the more interesting discussions regarding a precedent-setting incident for a league that is now 100 years old. One part of that incident set a viewing precedent for me, anyway. Rare indeed. This is coming from someone who watched his first NFL game about 60 seasons ago. I have never before witnessed any player swing a helmet at either somebody's protected or unprotected coconut. The incident was fascinating enough to briefly bring me out of forum hibernation.
From my viewing experience, virtually every misconduct exhibited during this overall incident has been repeated countless times over many, many seasons, all except for the most egregious one. There is personal foul history aplenty that can be used as a precedent towards the application of appropriate fines and suspensions for all but one of those active participants. Regarding all of the others: MEH, although special mention (and suspension) will always be deserved for intentionally kicking an occupied uniform, especially a helmet.
Now for the biggest offense: Some may want to stress any supportive details of "the Devil made him do it" defense that precipitated the helmet fiasco. Have at it. Personally, I could not care less who or what (lesser) act caused the escalation. Head-bashing is unjustifiable regardless of what lights the fuse. Importantly, the baseline punishment has now been established for non-injurious helmet clocking, an isolated incident that was unarguably way over the top.
May it be at least another 100 years before this type of incident occurs again, if ever.