No, Jimmy G wasn't a factor this off-season, obviously. But since you brought him up, when Belichick first had designs on JG supplanting Brady, that also was a massive miscalculation because Brady still had plenty of elite quarterbacking left in him. The returns on Brady only started diminishing as Belichick was unwittingly emptying out the cupboard. Had Belichick just trusted Brady, and surrounded him with an adequate supporting cast, they would be cruising to another division title with a 12-4 record. The point being, no matter how you frame the argument, Belichick is responsible for this season ultimately being a fail.