To be clear, I don't think those were unique cases that shouldn't be counted. I think they were cases of players they took a chance on and carried on the roster when many other teams wouldn't. In a lot of NFL cities, Josh Brent's career is over after the accident, period, and his 10 games never show up on their suspension ledger. In Dallas, he gets another shot.
Same for McClain. Really, in McClain's case I think the team carried him last year for bookkeeping reasons, because it somehow allowed them to get back some of the money they paid him. I don't remember the specifics, but there was a rationale for it.
The point is, these aren't discipline problems. This is a part of how the organization goes about finding or trying to reclaim players. I have no problem with you not liking it. I'm not a huge fan myself because it hasn't proven to be effective. But that's not what you asked. You asked if the HC was getting a pass for lack of discipline based off of a count of players' games suspended. He pretty obviously isn't.