He could have thought he saw something regarding your friend.

If he saw nothing and just assumed, it would be profiling if he has a lot of Canadians coming in and eating candy bars.

I doubt that he would just make up that someone ate a candy bar and point out the single Canadian. He might be naturally suspicious and saw your friend with his hand near his mouth and then jumped to the conclusion that because he bought a candy bar, he might have been eating one earlier. Maybe your friend was dressed the same as someone else who ate candy bars in the store before and he's assuming it's the same guy?

I wouldn't call it racist.