As he left the tribunal Lord Kilclooney refused to comment on his remarks that 13 gunmen were killed on Bloody Sunday.
‘‘I have given my evidence to the inquiry,’’ he said before getting into a waiting car outside the Guildhall.
Earlier, in his evidence, he backed hotly contested claims that one of those killed on Bloody Sunday possessed a nail bomb.
The family of Gerald Donaghey, 17, vehemently deny allegations that their son had any weapons and argue they were planted in his pockets by security forces after he died.
But the UUP peer told the inquiry: ‘‘I certainly have a recollection that nail bombs were used against the Army, and I think in fact one of those who was shot dead was found with one in his pocket.’’
He also insisted former Prime Minister Edward Heath would not have sanctioned any plans to kill rioters.
As a junior home affairs minister in the Stormont Cabinet in 1972, he sat on the Joint Security Committee (JSC) with Northern Ireland Prime Minister Brian Faulkner and top-ranking police and army personnel.
Lord Gifford QC, representing the family of 22-year-old James Wray, pressed him on a memo sent by General Robert Ford, commander of landforces in Northern Ireland to Brigadier Harry Tuzo, the GOC in the province at the time.
Gen Ford had suggested it may be necessary to shoot ringleaders among rioters in the city after clear warnings have been issued.
After Lord Kilclooney pointed out the legal barriers to any such plan Lord Gifford put it to him that the JSC had agreed the march in Londonderry had to be stopped by lethal force if necessary.
The UUP peer rejected this claim, insisting the authority lay with Mr Heath and military chiefs.
He said: ‘‘The final decision was taken in London, but I would not suggest for one moment that Mr Heath would have agreed to shooting rioters dead.’’
This echoed the view laid out in his statement to the inquiry.
‘‘At no time did the JSC ever hear of a suggestion such as this set out by Gen Ford,’’ he said.
‘‘If the JSC had been consulted about such an option, I would have been horrified.’’