Wallace states that he doesn't know if it's true, but he "read on the Internet that Elvis died with 40 pounds of undigested feces still in his intestine." As a former medical school student, one would hope that Wallace knows that feces is, in fact, the remains of already-digested food.
(at around 13 mins) Wallace explains what "Fools Gold" is. He talks of coating the inside with an entire jar of peanut butter as well as a jar of jam. After that, you see Chantry typing an email to Wallace, below which you can see Wallace's original email about Fools Gold. This email, however, doesn't talk about a jar of peanut butter. Just jam.
Right at the start Wallace and Chantry are toasting with two bottles of beer. When they toast both bottles have their caps on. Chantry walks away and we see Wallace drinking form his (now cap-less) bottle)
Chantry and Wallace meet at a party at Allan's place. At Chantry's going-away party near the end of the movie, much of the wallpaper looks the same as earlier, so it appears to also be at Allan's apartment. But both the color and pattern of the wallpaper behind the refrigerator are different between the two parties.
Cultural mistranslations: (1) Allan introduces Wallace as his "roommate from college." Unless they were educated in the US (and we don't actually know this), Wallace and Allan would be "roommates from university." Canadians don't colloquially refer to university as college. (2) Nicole suggests at one point that they discuss "topical events" of the day, such as gay marriage and abortion. These issues are not topical at all in Canada. They have been long settled.