As long the distribution was used to cover qualified educational expenses, he does not have to report it on his return - you can disregard it and file it in your records.
You cannot, however, "double-dip". In other words, if you are claiming an education credit (for him) on your return, you cannot claim the same expenses he is using to get tax-free treatment of his 1099-Q distribution.
See @HalAl 's answer in the middle of the following post: My son is nondependent who files own income tax. We withdrew 529 funds and used for his education. O...
