Buffalo Bills head coach Sean McDermott just issued a mea culpa ... telling media members Thursday he's truly sorry for bringing up the 9/11 attacks in a motivational speech a couple years ago.
According to GoLongTD.com's Tyler Dunne ... McDermott's tone-deaf talk to his players happened during the Bills' 2021 training camp -- when he was trying to emphasize to his squad how it needed to communicate to come together.
"Sources on-hand say, he used a strange model: the terrorists on Sept.