I cant recall if the trainer was there when the ball was played just beside him, i doubt it - wouldve been too quick, but an injured player that close to the action the ref shouldve halted play for his safety
Hoffman gets up, plays the ball and is then pushed back to the ground. He starts to crawl away from the try line as the next play the ball ensues. You can see the trainer (wearing red) run in at this point. Another trainer (wearing blue) stands at the back of play.
Play continues, Broncos kick across field, Raiders gather the ball and tackled 10 out from their own line. Papalii run is brought down just short of the 40. Jack Wighton then takes the ball up to the 50 and is brought down for the third tackle.
At this point you can clearly see the trainer in blue, who stayed with the defensive line the entire time, go up to the referee marking the ten and point downfield at the injured player. The referee then stops play, seemingly at the request of the trainer in blue.
I was keeping an eye on Hoffman at the game and the trainer with him did not signal to the referee that there was a serious injury.
Furthermore, and you couldn't see this on Fox Sports, but there were actually two Broncos down in back play. I can't remember who the other guy was but he had leg cramps and couldn't get back onside.