His response to a “heckler” saying “not good” is immediate proof of where he places the blame for a terrible performance: at the feet of the players.
“Do you want to come down here and try to tackle?” - Notice he didn’t ask “Do you want to come up in the press box and call plays?” Or “Do you want to come break down film and put a game plan together?”
In Tuiaki’s mind, the issue boils down to the players not tackling. By simply blaming the players, he removes the burden of introspection and reevaluation from himself.
I’ve also commented on posts in the past of Tuiaki’s attitude and demeanor in his interactions with media. He talks like he’s a defensive coordinator with championships under his belt, top 5 defenses, multiple first round draft picks, a reputation for outclassing his opponents, and various other professional pelts on the wall.
It seems the general consensus is that he started the gig inexperienced, got the job because his best friend is the head coach, and has mostly underachieved as defensive coordinator at BYU. So I think that some professional humility would go a long way for him.