It doesn't take long, sustaining that kind of beserker rage takes a lot of effort. And Tyler came in just after two days of AUGH.
Eventually it all boils back down to punches and kicks, and when he hits with his right hook hard enough to yelp..he backs down to hold his sore arm and snuffle a bit, shaking.

It's dim enough that Shephard probably can't see the boy crying with frustration, but... not like he needs to see it to know it's happening.