Maple Leaf Foods Inc. chief executive Michael McCain’s decision to openly criticize U.S. foreign policy on Twitter is highly unusual for the leader of a publicly traded company in Canada, and experts questioned his use of a corporate account to do so.

Mr. McCain singled out “a narcissist in Washington” and “U.S. government leaders” for “needless, irresponsible” events ahead of the downing of Ukraine International Airlines Flight 752, which killed all 176 people on board last week, including at least 57 Canadians.

“I really believe that Michael’s comments should have been issued on a personal account,” said Andrea Lekushoff, president of Broad Reach Communications in Toronto. “I believe the company’s brand must be treated as a separate entity from the CEO.”

After initially insisting the plane had technical problems, Iran admitted late last week it unintentionally shot down the plane amid escalating tensions after the United States killed General Qassem Soleimani, a top Iranian military commander.

The wife and 11-year-old son of a Maple Leaf employee were killed, Mr. McCain wrote in messages posted to the company’s Twitter account Sunday evening.

“I am very angry, and time isn’t making me less angry,” Mr. McCain said in tweets he characterized as his personal reflections. “U.S. government leaders unconstrained by checks/balances, concocted an ill-conceived plan to divert focus from political woes.”

Maple Leaf’s business presence in the U.S. is increasing; the company is spending US$310-million to build a new plant protein facility in Indiana. The company’s share price was down about 1 per cent Monday.

Maple Leaf declined to comment further. “Michael would prefer to let the messages in his tweets speak for themselves,” Janet Riley, vice-president of communications and public affairs, said in an e-mail. “He felt the tragedy warranted his response.”

Mr. McCain has a personal Twitter account with only 262 followers, but the company said he does not use it.

Ms. Lekushoff said companies need protocols spelling out what content is appropriate for the brand to communicate, and that it should be respected by all employees. “A CEO can have a slightly different persona and voice than the company … but a brand is very strategic, and all communications need to be aligned with the brand promise,” she said. “While this really humanizes and communicates [Mr. McCain’s] suffering, it also touches on politics, which could have a larger impact on the business,” she said.

U.S. President Donald Trump frequently attacks critics, and Mr. McCain’s comments have become international news. Prime Minister Justin Trudeau has avoided pinning blame on the U.S. for the crash.

Mr. McCain’s tweets triggered an array of responses, as some supported his position on the U.S.’s role in its conflict with Iran, while others said the U.S. bears no responsibility for Iran’s move.

CEOs of Canadian companies are rarely active on social media, and avoid saying anything controversial or political. “The idea that a Canadian CEO should directly share such highly charged, emotionally raw comments on social media is unprecedented,” said Bob Pickard, a managing partner at National Public Relations. “[Mr. McCain] is of a certain stature and phase in his career where I think there’s probably less concern for the usual constraints of corporate compliance applying here.”

While Mr. Pickard said he would generally advise against CEOs sharing personal political views through company social-media channels, the tweets illustrate that business leaders can have a wide impact when they share fully how they feel about certain events. “Corporate communications is very machine-like, whereas if leaders speak like real people do, there is a profound effect,” he said.

Mr. McCain has a reputation for being outspoken and is seen as a savvy communicator. “His credibility in our industry is extremely high for the way he handled the 2008 listeria crisis,” said Jeff Lake, senior vice-president and managing partner at communications firm Punch Canada.

Mr. McCain was front and centre after tainted deli meat from the company led to the deaths of 22 people, and his openness with media at the time is seen as a textbook example of effective crisis communications strategy.