Near the end, the father of François Pignon tells him that he is invited to a dinner to talk about his corkscrews collection. This is a reference to another Francis Veber movie, The Dinner Game (1998), in which a likable idiot (also called François Pignon) is invited to a dinner on the pretext of talking about his match constructions.
When the president yells at Francois and his lawyer hang up the phone, you can see that the CISCO IP Phone is not even working and has the wrong date. There is no way someone would have been able to make a phone call using that phone.
Both Francois and Emilie purposely avoid going to Luigi's for lunch, but run into each other at another restaurant. However, in the next scene, Elena asks Francois "Did I upset the girl at Luigi's?"
Émilie agrees to marry Pignon after having a talk with Elena.
Elena receives a tape from Pierre's wife which makes her realize he won't be leaving his wife.And finally, Pierre is photographed on the street with a propositioning male prostitute.