But we don't know for certain that the penalty led to the rear-end failure, do we? It's possible to draw that conclusion but JJ's ass-end has been repeatedly abused by his crew chief and may have just plunb wore out!
I would say that the Kyle Larson / Ty Dillon dust-up was the biggest bonehead move of the weekend. Dillon should have let Larson go and Larson should have realized that he was going to potentially alter the Championship with his somewhat risky move.