Was he on medication and due to the length of being seizure free stopped the medication. Actually this happened to me. I had an attack in 1985 and then in 1996 it was caused due to my expertise thinking I do not need the medication. Then in 2003 when I moved to Canada, my Dr. from India thought the same way and slowly declined my medication dosage and finally stopped it in early 2004. Within 15 days of completely stopping the medication I got an attack again, and from that day onward never forget to take the medication.