I don't think the dishwasher ever signed the form before he was caught trying to leave the country with $59,000 in a duffel bag. Trying to take over $10,000 in cash or cash equivalents out of the country WITHOUT filling out the form could lead to civil forfeiture of the cash and if done willfully, is a crime.
I've been trying to find the judge's 6 page opinion on the Internet, but haven't yet.
You are correct, the story says he failed to sign a form, I assume that means he didn't fill one out and turn it in.
That is slightly in his favor in my mind, simply because falsely filling out the form would prove intent to deceive, while not filling out the form could indicate ignorance.