I am guessing he is planning on returning later, right? Don't you think he is going to have trouble coming back if his departure hasn't been recorded?

Sorry, I don't have any personal experience or knowledge on this topic. Just wanted to let you know that the above question was the first thing that came to my mind. Also, I don't think "Urgent Help" is the appropriate title for this post.

Here's a link that might be helpful: https://help.cbp.gov/app/answers/detail/a_id/752

This isn't exactly your question but this might be helpful:

I did not turn in my I-94 when I left the U.S., what should I do?

If you returned home with your Form I-94 (white) or Form I-94W (green) Departure Record in your passport, it is possible that your departure was not recorded properly.If you departed by a commercial air or sea carrier (airlines or cruise ships), your departure from the U.S. can be independently verified, and it is not necessary to take any further action, although holding on to your outbound (from the U.S.) boarding pass - if you still have it - can help expedite your reentry next time you come back to the United States.If you departed by land, private vessel or private plane, you will need to take steps to correct the record. If you do not validate your timely departure from the United States, or, if you cannot reasonably prove you departed within the time frame given to you when you entered, the next time you apply for admission to the U.S., Customs and Border Protection (CBP) may conclude you remained in the U.S. beyond your authorized stay. If this happens, your visa may be subject to cancellation or you may be returned immediately to your foreign point of origin.