I think they exceeded a limit on something... either mechanically or mentally. http://autos.yahoo.com/blogs/motoramic/shelby-gt500-shreds-dyno-canadian-fireworks-144623336.html It looks like one of the smaller, electric loading type dynos?
Watched that the other day. There is a trailer mounted dyno that a guy hauls around to some of the bigger car shows here. It always amazes me when they get it going, how many people crowd around it, including families with little kids. When they start it up, I head the other way just in case ................