No fullback is perfect, look at taa and robinson as prime examples. Tierney has his faults but the boy is class, he has arsenal in the way he plays and the way he acts. He is still young and in a few years he could be the best in europe and also our captain.
The whole "not enough bad guys" narrative is so annoying. If players show character by standing up for themselves and their team-mates or call out others for their bullshit (like Tierney did there), I like to see that.
Pathetic stuff like Tierney's "head injury" (Evans did the same thing in the first half) on the other hand needs to get out of the game and be punished with suspensions.