I think the reason that became a story was Greg Olsen in the booth repeatedly saying saying yeah he tugged but they shouldn't have called a penalty at that point in the game. I couldn't have disagreed with him more.
Earlier in the game he did the same thing and there was no call. What makes this so controversial is that human element in which there's often inconsistencies.
That said, there was another official call that could have changed the entire game but fortunately or unfortunately has been mandated by league rules. The play in question was a reversal of catch/no catch fumble return for score.