With the possible exception of the tuck rule, the rule that tripped up the Lions and Jim Schwartz has to be one of the dumbest in the game. You don't have to throw the challenge flag because we'll review it on our own, the rulebook says, but if you throw the challenge flag we won't review it.
Everyone screwed up here. The refs, for not seeing that Justin Forsett's elbow and knee hit the ground, before he got back up to scamper 81 yards for a touchdown. Jim Schwartz, for trying a challenge when he wasn't allowed. (I think we can afford to be a little hypocritical. Even if we didn't know you could actually skunk a booth review by tossing the flag, it's a head coach's job to know it.) And the rulebook itself—I can't see what situation this was intended to address, what wrong it was designed to right.
It's no surprise that the league is probably going to change the illegal challenge rule, and they may not even wait until the offseason.
"I knew the rule, that you can't challenge on a turnover or a scoring play, but I was so mad that I overreacted," Schwartz said. "I had the flag out of my pocket before he even scored the touchdown, and that's all my fault."
"It's on me," Schwartz told his player on the sideline at the time. But how much of an effect on the game's outcome did his blunder actually have? Advanced NFL Stats calculated the win probabilities for the Texans had Forsett been ruled down, and what actually happened. Third and 2 at Houston's own 27 would have given them a WP of 0.18. A touchdown and touchback on the ensuing kickoff give them a WP of 0.35. One poorly timed red flag nearly doubled the Texans' odds of winning.
Of course, the point is moot if Detroit wins in overtime. Choosing to kick a 47-yard field goal on third down, rather than pick up a few more yards, is inexplicable. The loss is on Jim Schwartz, not because of any one play.