It could be worse. If he is caught lying (not that it is easy, see my comment above), he can be denied entrance to the US for 5-10 years.
Being denied entry is enough to be excluded from the Visa Weaver program. He needs to get at a minimum a 6 month multiple entry tourist visa in order to enter the U.S. now. They will still take him for extra questioning each time he enters. It will take hours each time.
How does the US correlate the two files if you change your name in your home country?
When you apply for a visa, they take your fingerprints.