ST. JOHN'S, N.L. -- The Newfoundland officer who says he shot Don Dunphy in self-defence admits there was "nothing concrete" to suggest Dunphy posed any threat prior to the fatal confrontation.

"I had no reason to believe that Mr. Dunphy would act out violently," Const. Joe Smyth of the Royal Newfoundland Constabulary told a public inquiry Monday into the killing.

Still, Smyth said under cross-examination that he found some "disconcerting" comments after reviewing about a year of Dunphy's frequent Twitter posts.

Smyth had gone alone and unannounced to Dunphy's house in Mitchell's Brook on Easter Sunday 2015 after staff in then-premier Paul Davis's office flagged comments on Twitter.

Smyth says Dunphy, 59, invited him in but the conversation suddenly got heated just before Dunphy reached beside his recliner and aimed a .22-calibre rifle at him.

Lawyer Bob Simmonds, representing Dunphy's daughter, had Smyth confirm that his job as a former member of then-premier Paul Davis's security detail was primarily to protect Davis and elected officials from physical harm.

He repeatedly grilled Smyth on why he gave several people the impression -- including an RCMP officer -- that he was visiting Dunphy to assess a "threat" against the premier. He also questioned him on comments at the time by Smyth suggesting disgruntled citizens who vent on social media "don't realize there are consequences for these statements."

"What are the consequences?" Simmonds asked, noting that Dunphy, a disgruntled injured worker, was engaged in lawful free speech and never threatened violence.

Smyth agreed, but maintained he found some of Dunphy's Twitter posts troubling. They had, after all, been flagged by the former premier's staff as a concern, he said.

Simmonds pressed on.

"You had no basis at all -- zero -- to believe Mr. Dunphy would be violent, act out or be anything but appropriate with you," he said.

It's the first chance other lawyers have had to cross-examine Smyth since commission co-counsel Sandra Chaytor finished more than three days of questioning. She wrapped up Monday by asking Smyth if there's anything he could have done differently.

"I could have not went there," Smyth said.

Also Monday, Smyth said he saw no conflict in sending an email explaining his actions to the lead RCMP investigator and about 400 other RNC and RCMP officers.

"I didn't see it as being a conflict" or having an impact on the probe, Smyth said.

He said the email, which was leaked to media on the day of Dunphy's funeral, was to urge co-workers to reach out to troubled individuals.

He stressed that although he sent the email -- signed "Joey" -- to so many people he never meant for it to be shared beyond the police community.

"I was almost sick to my stomach," Smyth said of the realization it had been leaked to media on the day of Dunphy's funeral April 10, 2015 held five days after he was killed.

"This is such bad timing," he recalled thinking, and said he thought of the family.

Smyth said it hadn't occurred to him the email might be leaked.

Smyth admitted, though, that an email he later sent directly to lead RCMP investigator Cpl. Steve Burke was "probably" inappropriate.

Smyth sent it past 3 a.m. on July 29, 2015 asking Burke for an update.

Smyth told the inquiry he was at that point increasingly frustrated being in "professional limbo." He'd been put on a desk job after serving as an acting sergeant in the premier's security detail.

"I'm lying wide awake" thinking about what happened as he had many nights before and since, Smyth said when commission co-counsel Sandra Chaytor asked about the hour he sent the emails.

Burke responded that it would be inappropriate to discuss the investigation.

Smyth took several months of stress and parental leave starting that fall. He now works in traffic operations.

Commission hearings will continue into March. Inquiry Commissioner Leo Barry will not make findings of civil or criminal responsibility, but any new evidence could be investigated by police.

His report is due by July 1.