Will my friend with an Ed visa need to leave Thailand immediately after it expires if he returns with a re-entry permit?

The question concerns an individual with an Ed visa who will return to Thailand with a re-entry permit shortly before his visa expires. Forum members clarify that although the visa technically expires the day after his return, he may not need to leave immediately, as American citizens typically receive a 30-day visa exemption upon entry. However, the final decision lies with immigration officers, and there is some uncertainty regarding how strict enforcement may be on the expiration dates.