What if Suaad Hagi Mohamud really had been an imposter? Instead of being the Somali-born, Toronto mom she claimed to be, what if she had been a terrorist? Suppose she had boarded a Canada-bound flight from Nairobi, Kenya and instead of disembarking at the other end with gifts for her 12-year-old son, she had blown up the plane. We would all now be criticizing as too lax those officials who revoked her passport when she attempted to leave Africa in May. When it comes to security post-9/11, it's best to err on the side of caution.

But this broad principle cannot serve as a blanket excuse for all forms of behaviour by our diplomats, security officials and bureaucrats. Had Ms. Mohamud been detained for a few days and then released after her identity was proven, that would be one thing. But she has endured a two-and-a-half-month nightmare. And so our sympathies lie with her.

Thankfully, the kind of mistakes made by Canadian and Kenyan officials in mis-identifying Ms. Mohamud are rare. Nonetheless, an investigation must be conducted into how and why this problem occurred.

It's easy to understand how Kenyan passport screeners might have concluded she was not who she claimed to be:Who among us looks exactly like his or her passport mug shot? Harder to figure, though, is how Canadian investigators could claim that their own "conclusive investigations" proved she was an "imposter."

What methods did they use to establish this so definitively? We know Ms. Mohamud consented to having the fingerprints on her citizenship application checked against those her Kenyan jailers had taken, but we also know her citizenship documents had disappeared. If Canada Border Security Agency and Foreign Affairs bureaucrats could not check her prints, and had not until recently done a DNA match, just what "conclusive" techniques did they employ? Canadians such as Ms. Mohamud, who travel abroad each year by the millions, need to know they can count on Canadian consular officials if they are wrongfully detained overseas.

Being Canadian is not a "Get Out of Jail Free" card for travelers --as some apparently expect it to be. But Ms. Mohamud committed no crime. And so she is owed an apology. More importantly, she and other Canadians are owed assurances that everything that can is being done to ensure her nightmare will not be repeated.