At this point I'm mystified that anybody could say that Berman's reasoning is "questionable" or "surprising." I think the points he discussed in the ruling have been well-developed, much-discussed, and are fairly straightforward.
Goodell punished Brady for something that is not specifically listed as a punishable offense for players in the CBA, and the punishment that he chose was drastically more severe than any written punishment guideline that the league can reference. On top of that, there's simply no precedent for punishing a player with a 4 game suspension for either tampering with equipment or impeding a league investigation.
Munson really sounds like a league shill.