Well if he didn't sign the certified letter that came in the mail then the court cannot prove notification so a driving on suspended would not hold up in court unless he tells the arresting officer that his license is suspended which would be an admission of guilt.

The only reason I can see getting your license suspended for something like is if you violated your points alotment from DMV (ie: 12 points in a year, 18 in 2 yrs etc) that violation by itself isn't one where your license can be taken away.