Intent to evade tax/unreported vehicle purchase?

My husband bought a motorcycle for 8,000 and like an idiot talked the guy into writing a bill of sale for $100 to avoid paying taxes on his bike. Because he took out a loan to pay for his bike the State Tax Comission caught him and he was sent out a certified letter with a $500 fine. My question is after the fine has been paid will there be any other penalties? Will this go on his record? Or will this be over after the payment has been made? Thanks