I legit thought Sal was wrong with the $70M figure. He was not (obviously). Here’s a link to Spotrac for those of us who are having formatting problems with the list posted:
https://www.spotrac.com/nfl/buffalo-bills/cap/2018/
It is not unusual to have a lot of dead cap when there’s a purge of players. Add in a few recent mistakes and some bad luck and that’s what you get. However it should be noted that the current dead cap number for 2019 will rise as players get cut, traded, etc this season.