Sounds like she may have accidentally had the park brake on. You even mentioned yourself that it couldnt have been unnoticed due to the obvious feeling of the brake being dragged, but the parts show differently. She should have noticed that the brakes were dragging like that regardless of the cause. Probably just an honest mistake. It happens. Youll be lucky to get warranty on that, but good luck. Let us know how it turns out.
The brake wasn't dragging. The sled was performing perfectly. There were absolutely no indications that the brake was even being applied.