Police in Sherbrooke, Que., have arrested a 22-year-old waiter for serving salmon tartare to a client who ordered beef tartare and had warned him he was allergic to seafood.

But securing a conviction for criminal negligence — a prospect raised by police on Thursday — could be difficult.

If Crown prosecutors decide to press charges, the waiter is likely to be accused of criminal negligence causing bodily harm. Gatineau, Que., resident Simon-Pierre Canuel said he went into anaphylactic shock and had a cardiac arrest that left him in a coma for several days after eating salmon tartare instead of the beef tartare he had ordered.

In order to convict the waiter, the Crown would have to establish that he displayed extreme carelessness toward the client's safety, said one criminal defence lawyer.

"Criminal negligence requires a reckless disregard for human life," Eric Sutton told CBC's Radio Noon. "It's not enough to be negligent or careless. You need more than that."

Sutton is unconvinced the Crown will pursue a case against the waiter.

Simon-Pierre Canuel says he was in a coma for several days and 'almost died' after being served salmon by a waiter who was aware of his allergy. (Submitted by Simon-Pierre Canuel) The case appears to be unlike any other reported finding of criminal negligence. A classic case, Sutton offered by way of example, would be a doctor amputating the wrong limb of an anesthetized patient: "The victim is completely helpless and vulnerable."

It is not clear such a description would apply to Canuel, he said. As someone with a life-threatening food allergy, he, too, has responsibilities. Canuel, moreover, left his EpiPen in his car.

"I think every time you see salmon in a restaurant, and you have an allergy of that severity, you have a responsibility to be aware of what you're doing."

Nut allergy precedent?

Several legal observers, including the police force that made the arrest, believe the Sherbrooke case marks the first time a waiter has been arrested for endangering a client.

But it does contain a number of parallels with a 2006 civil case in Saskatchewan.

A hunter from North Dakota with a nut allergy sued a waitress and the owner of a Travelodge Hotel in Melfort where he suffered an allergic reaction.

Before ordering a cheesecake from the restaurant, the hunter asked the waitress if it contained nuts.

An EpiPen epinephrine autoinjector can be used in cases of a severe allergic reaction. A 2015 new report suggests the number of Canadians who visited hospital emergency rooms for anaphylaxis has doubled in the last seven years. (Carlos Osorio/Associated Press)

The waitress said it didn't and served the hunter a slice of cake. Upon taking a bite, the hunter declared he tasted nuts. He suffered an anaphylactic reaction and had to receive several injections of epinephrine at a nearby hospital.

The judge in the civil suit determined that the waitress had a "duty of care" to her client, which she violated by failing to check whether the cake contained nuts.

As it turned out, the cheesecake package indicated that it was made with walnuts. In the 2011 ruling, the waitress and the restaurant owner were ordered to pay the hunter $25,000 in damages.

"The standard of care for [the waitress] was to ascertain that the cheesecake did not contain nuts, something that [the hunter] would have done himself if he had been acquiring the cheesecake directly," the ruling reads.

Canuel, the victim in the Sherbrooke case, has already taken the first steps to file a civil suit against the restaurant.