When Homer gets food poisoning and runs to a nearby bathroom, he runs down a hallway which is inconsistent for the Simpson house; he clearly runs from Living Room to the TV Room and should've been in the kitchen at this point.
When Krusty goes to take a bite, the close up isn't him at all. The man in the close up's face is yellow, not white, and he has a regular pair of lips, not the monkey style like Krusty and Homer. This is, of course, on purpose, to imply that Krusty didn't really eat the burger, and that the commercial's production values are shoddy.
Homer mentions he has "xylophobia" which Lisa tries to correct him to xenophobia stating xylophobia would be a fear of xylophones. Xylophobia is a fear of wood, not xylophones.