Revealing mistake: While John drives the minivan, there's a closeup of the rearview mirror's reflection as he spots the first BMW tailing them, but the problem is the view we see within the mirror is not backwards, even though it should be.
Character mistake: When the Smiths first enter the store Home Made, the camera pans around and faces the store's large display picture which reads, "The true measure of a home lies in it's kitchen," but the word "it's" should be "its."
Revealing mistake: While Jane drives the minivan, after John tells her that he knew he saw her "father" on Fantasy Island, there's a closeup of the rearview mirror's reflection just as Jane sees the two BMWs still chasing them, but the view we see within the mirror's reflection is not backwards.
Continuity mistake: While John's standing at the minivan's open rear door hitting the guy with the golf club, we can see that the van's rear-view mirror has been removed for this shot, but it's back in its place in following shots.
Continuity mistake: While the Smiths are hiding out in the small shed in Home Made, at one point Jane's glasses are folded and hanging from her neckline with the nose guards facing her right, but in the next shot the glasses are facing her left, then it's back to her right, and finally her left again.
Continuity mistake: When John comes home to the lovely pot roast dinner he places his martini glass on the table, and when Jane takes the skewered olives in the closeup there are three, but in the wideshot there are only two olives on the pick as Jane puts it in her mouth.
Continuity mistake: When Jane opens the minivan's hatch the driver's side window is already shattered, before it actually happens.
Continuity mistake: After John hits the guy with the golf club he pulls the grenade pin, and when John dives back into the minivan he knocks down the rod holding the dry cleaning hangers, but then the rod is back up again without the hangers, and when the last two BMWs are taken out, the dry cleaning hangers are back up as well.
Continuity mistake: After John fakes his death in the falling elevator, in the wideshots he reaches up with his left hand to disconnect his video feed, but in the closeup it's his right hand disconnecting it.
Factual error: When they race home Jane T-bones John and caves in the side of his car, but her car shows no damage. A modern Mercedes (2005) is designed to crumple in such an impact.
Continuity mistake: In the store, John takes out two mercenaries with a pipe wrench. They had suppressed MP5s. When Jane and John take the weapons, the suppressors have gone. (01:44:17)
Other mistake: In the hunt out in the wilderness - where Jane looks in the binoculars - there is a cover on one lens - but it shows you can see both sides. (00:30:27)
Continuity mistake: During the scene when John and Jane are dancing in the hotel restaurant when they first start to dance the large set of windows are behind them but once they start to move just before he knocks her head into the mirror breaking it they now have the large window still in the shot but now on the left side of them even though they never turned except there is a cut. (01:03:22)
Answer: She notices that he shakes his right leg twice after peeing, just like her husband.