I've been using Challenger 2 post lifts for over 30 years and I really like them. Now the lift that Vette was on was not positioned correctly by the operator (possibly someone who shouldn't be using it ) I have seen that happen before by a careless tech in our shop with a Celica. The car nose dived and when it did the arms went wacky but this was before they had positive locks on the arms. Some guys disable safety features on their lifts because they think it slows them down.

Gus