Ahh, much better.
Start listening around 9:40
Sounds like United just didn't start the takeoff roll in time (might have been slow to turn the corner).
Fortunately/Unfortunately, this is just part of the training process. Nobody has perfect performance during training. That's what the trainer is there for, to come in and put a stop to it when things start going bad.
As a former tower trainer, it can be a slow and painful process at times.