I have been motocrossing since I was 11. Two things you learn really fast. The first thing you learn is that you DO NOT ride fast until you are familiar with the path, course, track, etc. Ditches, wetlands, etc can come up on you faster than you can react. The second thing you learn is you NEVER ride fast on a bike you are not familiar with. The powerband, braking, steering (especially on YZ's), handling, etc is all different.
Now, translate to cars. One thing I NEVER do is drive "spirited" in unfamiliar territory...and I rent exotics all the time when I travel. The second thing I never do is push these cars until I have at least a day or of driving them and I am familiar with the streets, tracks, etc that I am driving on.
Bottom line is this cop was a fool. Plain and simple. And quite honestly, the guys renting this guy a Viper were foolish as well. Next thing you know you will be able to rent a 1400 cc Suzuki Hyabusa...all you will need is a license and a credit card....and maybe a well written Will.