The Royal Canadian Mounted Police (RCMP) unit responsible for coordinating airport security was often not tipped about threats and warnings that preceded the 1985 Air India bombing, the inquiry into the disaster was told.
Former sergeant Joe MacDonald, who ran the airport policing branch at RCMP headquarters at the time, said before the inquiry commission on Monday that he was surprised that he did not receive some of the documents, which included warnings of potential hijackings, airline bombings and suicide attacks.
One dated August 1984 warned that Sikh extremists planned to blow up a Boeing plane leaving Montreal and London.
But MacDonald was never notified at headquarters - a failure that he said was probably due to the sheer volume and frequency of the threats.
MacDonald himself was responsible for one communications breakdown, when he failed to pass information he did receive from Air India to the Canadian Security Intelligence Service.
The airline had told the Mounties it feared either a bombing or a suicide attack sometime in June 1985. "I saw no need to send that one (to CSIS)," said MacDonald. He offered no detailed explanation for the action: "It's just a decision you make at the time."
MacDonald also said that the Canadian Police and Transport Canada - responsible for aviation management - were entangled in a dispute over who would pay for additional security cost for Air India in the weeks leading up to the bombing that claimed 329 lives.
However, MacDonald said the spat didn't mean the airline was left unprotected from terrorist threats.
"It didn't affect the coverage. They continued with the coverage (and said) basically we'll worry about the money later. But the arguments were going on all the time," he testified.
The security coverage given to Air India - categorised as "level 4", the second-highest possible - called for RCMP officers to be deployed at check-in counters, arrival and departure lounges, and for a cruiser to be stationed on the tarmac near the aircraft.
Level 4 was also supposed to mean an RCMP sniffer dog would be on call to check suspect luggage pulled aside during the pre-boarding process.
As a rule, said MacDonald that was no problem: "The dogs were at the airport, they were stationed at the airport. They didn't have duties off the airport." But it's known from documents tabled at the inquiry that no dogs were used to screen the luggage loaded aboard Air India Flight 182 before it departed Pearson Airport in Toronto on June 22, 1985.
It's not clear exactly why that was the case. The inquiry is expected to delve into the matter when other police and Transport Canada officials testify later this week.
No RCMP dog was on hand either when the plane stopped later that night at Montreal's Mirabel Airport. A Quebec provincial police dog handler was called in as a backup - but the plane took off before he arrived at the airport.
The failure to properly employ the canine teams marked the end of a long series of security oversights. An X-ray machine at Pearson also broke down during luggage screening, and a hand-held electronic wand proved to be ineffective in detecting explosives.