Depends on what type of money they think he owes. An attorney is going to cost him; if the amount at-issue is small, then it may cost him more to hire an attorney than to just pay them what they think he owes, to go away.
I agree. Depends on how bad the penalty is. However, I would lawyer up with the best damn pit bull ex IRS tax attorney I could find. These people have all the time in the world and all the money to prosecute you. AND THEY WILL. Make no mistake, they love to make examples of honest citizens who make mistakes. Kind of like kicking the victim while they are down and selective law enforcement. Watch your ass.