would probably hold their nose and hide behind "letting the legal process play out" but because he hasn't been that good in his first two years they will cut him loose and try to claw back some money/salary cap space.
As a first round pick, his salary for this year and next had been guaranteed. But those guarantees are for skill, injury, etc. If the Lions want to play hardball they can claim conduct detrimental, akin to firing someone for cause, and try to get out of it. Presumably there would be a grievance filed and some arbitration process if they do. Similarly they could try to claw back some of his signing bonus, but they would only get credit back on the salary cap if they actually recover the money, just demanding it back isn't enough.
I saw a Reddit post which pointed out he was ranked 72nd out of 72 (those beyond some threshold of playing time/snaps) at his position last year by one metric, DVOA. It is never good for your career to be dead last like that, regardless of where you were drafted. Add on some felonies and the Lions' decision couldn't have been easier.