After Steve (Will Ferrell) and Emily (Molly Shannon) get engaged, Emily starts putting several of Steve's possessions in a cardboard box to throw away (his going-out clothing, a disco ball, etc.). Emily also grabs his silver chain necklace, tears it off, and throws it in the cardboard box with the rest. Steve then has his necklace on shortly thereafter.
On their way to their father's "fake plant shop", the Butabi brothers pass the lamp shop on their left. This shop is supposedly right next to their father's store (to the left), yet they keep walking for a few more minutes. Then we see them walk into their father's store coming from the right, when they should've walked in from the other direction.
When Steve is talking to his Dad in the kitchen, during dinner with the Sandersons, we see Mr. Butabi with a bottle of wine that he just uncorked. In the next shot, we see the cork in his hand, but we hear and see him pull it out again at the end of the scene.
When Dooey had Doug and Steve kicked out of Zadir's office, we see him following the guards down the hall. He jumps from halfway down the hall, back to Zadir's door to tell Zadir that it was just a couple trespassers.