The tribunal was set up to look at claims the movements of chief superintendent Harry Breen and superintendent Bob Buchanan were leaked to the IRA by a “mole” in Dundalk garda station.
Denis Dullaghan told the tribunal he saw the helicopters as he drove towards a petrol station near the ambush scene, and after he left the station he was stopped by a local man who told him two people had been shot.
There was no ambulance or police when he arrived at the scene, Mr Dullaghan said.
Tribunal counsel Ms Mary Laverty said the tribunal had previously heard reports that superintendent Buchanan was “careless”, using the same car and route on several border crossings, but that “it occurred to me maybe on this occasion he was being escorted.”
Earlier, lawyers for three former Gardai identified by the as possible source of the alleged leak clashed with the Smithwick tribunal chairman over their clients’ past records.
Solicitor James McGuill, representing former sergeant Finbarr Hickey, said a criminal conviction against his client years after the deaths of RUC chief superintendent Harry Breen and superintendent Bob Buchanan in 1989 should not mean that his client was “retried” at the tribunal, as it was outside the terms of reference.
He said the uncontested evidence at the inquiry was that Hickey was not in Dundalk garda station on the day the two RUC men visited, and could not have known about their visit.
But tribunal chairman Peter Smithwick disagreed, saying that Hickey had been convicted of obtaining forged passports which assisted the IRA.
Mr McGuill said this was a “mischievous” suggestion, which he was “absolutely astonished” to hear, and the State’s case against his client was that he did not know the IRA were the ultimate beneficiaries of the passports.
“He was not colluding, certainly,” Mr Smithwick said at the end of the exchange.
Lawyers for retired sergeant Leo Colter pointed out that their client had not been convicted of any offence, and denied any allegations. Mr Hickey has claimed that he provided false information for passports at the instigation of Mr Colton.
And Darren Lehane, representing ex-sergeant Owen Corrigan, said breaches of discipline by his client were not relevant to the tribunal.
Later, retired garda superintendent Tom Connolly recounted an incident where sergeant Corrigan took an unmarked detective branch car without permission.
The car was missing for several hours, and an investigation later showed it had travelled over 200 miles.
Mr Connolly said an investigation showed that Sergeant Corrigan had altered the mileage log book for the car.
Mr Corrigan was later disciplined for the unauthorised use of the car, and fined.
Mr Connolly wrote in a report that the sergeant was a bad example to younger Gardai, and had a bad reputation among members of the Gardai and civilians, and was “prone to fabricate evidence”.
And he said he was told that Garda Superintendent Pat Culhane (deceased) had met with an RTÉ producer over a programme which planned to name Mr Corrigan in connection with smuggling allegations.
But he agreed that reports of “unease” about Mr Corrigan in Dundalk were hearsay, and he had no evidence to support any allegation.
“I was repeating what I was told,” he said. “Whether there was any truth to it I don’t know.”