But, did he remember to track and deduct all of his expenses? The flipside to that income is that the server costs are all deducted from it. If he really was "just barely covering costs" with his Google ads income, it should be 15.3% of nearly zero dollars. He may even be owed a refund if he was paying full income tax on the ad revenue without deducting server costs.
I am not an accountant, but I've dealt with SE tax and had a few "conversations" with the IRS in the past. For all the worries about them being biased, I've found them to be fair, as long as you have precise documentation.