I'm guessing Richards failed a drug test and L.A. is going to use that as an excuse to terminate rather than buy-out his contract.
I don't think that would work. The NHL has substance abuse programs and the player would have to go through there first. I really do not think the team could terminate a contract over a substance issue - especially if the player hasn't sought assistance yet.
And if you're talking about performance enhancing drugs, that's a league thing, not a team thing. And the penalty if caught isn't contract termination, but a series of suspensions (20 games, 40 games, season, etc).