So what that it had no effect on the gameplay. The NFL made a rule to protect refs from harassment of players and coaches from the sidelines, if you don't like the rule then so be it.
Here's a quote from Dungy on it.
"To me," Dungy said on "The Dan Patrick Show," Dez Bryant's actions were "worse than the pass-interference call. You can debate the pass-interference call. The helmet rule is plain. And for an official to not have the courage to call that. Dez Bryant is not on the field at the time. He is an offensive player not coming in as a substitute. There is no reason he is out there other than to argue the call with no helmet on. Every official should have thrown a flag at that point. At the very least it should have been another 15-yard penalty. And there is no way you can justify not calling that."
Read more:
http://www.businessinsider.com/dez-...ce-penalty-cowboys-lions-2015-1#ixzz3NyCITMaV