It’s an endurance racing rule. Pit members have to stay behind a line until the car is stopped in the box. Therefore the countdown simulates the car pulling into the box and stopping. In the states the crew can jump over before the car gets to the box and will be on the outside. I wonder if they won the pit competition though. That was still quick

There are differences of opinion on what causes the wheels to fall off. NASCAR insists that it’s the pit crews failing to tighten them properly, but teams have pointed to issues with the way the wheels seat to the hub. We have also seen issues with the single lug basically welding itself to the wheel, which presumably damages the threads when the team is finally able to remove it.