"He has a driving with out insurance conviction but that is spent this year."
US don't accept the concept of "spent", however, as driving without insurance isn't a CiMT (something the question on ESTA still refers to), there is no problem in answering 'no' to the question on ESTA.
Moral turpitude has been defined as an
"act of baseness, vileness, or depravity in the private and social duties which a man owes to his fellowmen, or to society in general, contrary to the accepted and customary rule of right and duty between man and man."
Now, forgetting (accidentally or deliberately) to insure a motor vehicle doesn't come close to that. There is also no cases that I can find that has defined driving without insurance to be moral turpitude.
If, in the very unlikely event, CBP ask him if he has ever been arrested when he arrives in the USA, that's a different question, and the answer would be "yes". Although there is no consequence as he can still use the VWP.
Post Edited (dannys) : 08/05/2016 13:51:27 (GMT+2)