His "income" and the "Modified adjusted gross income(MAGI)" that is used for figuring out the Roth eligibility may be very different.

He should check it out to find out the details of just what is excluded from the MAGI but it could have been reduced a lot by things like 401k contributions, flexible spending accounts, some pre-tax payroll deductions like for health care, etc.

If he did his tax with tax software I would be surprised if he able to do the Roth contribution if he was not eligible without at least getting a big warning that he would have to override.

Greg