If we look beyond the obvious that no employer is going to be interested in someone who facing potential murder charges...
Why would they make an exception for this player that will undoubtedly then be used by every player following him? How many risks do you take with your job that could get you fired? If he ended up charged and convicted, the outcry would be insane.
I would have liked the Bills to take the risk, but you can't blame any of the Teams or the NFL for taking a pass.