Mr McLarnon, who works as a general dental surgeon in Co Donegal, was at his girlfriend’s house in the Co Tyrone town on the day of the blast.
The Real IRA terrorists who bombed Omagh in 1998 seem to have been allowed to act with “impunity”, a witness has told a public inquiry.
He said: “There were two ladies….the older of the two ladies, one of her legs was virtually amputated, it was held on by skin only.
Mr McLarnon said he suffered from depression and trauma due to his experiences on the day of the bombing.
“I would have nightmares about what I had seen and I felt useless, guilt, anger and depressed about my inability to help anyone on the day of the bomb.