You pull 3.5 G’s when the brakes hit on that ride to slow the dropping tower. But that force is directing you down into the seat IF you are restrained. That means a 140 pound kid weighed around 500 pounds at that moment.
The related article in the NY Post notes that this 14 year old 'kid" was 6'5" and weighed 340 lbs! Given his size and weight he probably exceeded the ride's design limits.
From the NY Post article:The heartbroken dad is demanding to know why his 6-foot-5, 340-pound son was even allowed on the ride after he was stopped from getting on others due to his size.