My question involves criminal law for the state of: AZ

Is there any possible defense for someone who forgot to pay for an item that was in the rack underneath the shopping cart.? Is it possble to convince the court that it was just an stupid mistake ? The total bill was over $300, which was paid via live cashier (not self checkout), and the forgotten item was worth less than $5.
I'm sure everyone who steals probably claims that it was a mistake, and didn't mean to do it, so it seems futile to even to there. But if it really was just spacing out, should the person plead guilty and throw away their career ?
His career will be over, for sure, and that's alot to lose for a stupid ADD mistake. Any ideas?

Are there any examples of people who have actually been found not guilty of shoplifting in a case like this?
Thanks