When Barbra tries to escape, she throws a coffee mug at Ken, hitting his nose. You can see the plexiglass in front of Ken reflecting light on his shirt. Also, slowing down the frames, before the mug hits Ken, you can clearly see the cut mark already painted on his nose before the mug hits him.
Ken's first attempt to collect the ransom from Sam Stone happens on a Monday. When Sam fails to show, Ken reschedules the drop for Wednesday. Following the failed attempt, Sandy goes down to the basement to bring Barbara more magazines. Barbara asks how long she's going to be there, and Sandy says, "As soon as Mr. Stone pays the ransom. Should be Monday." The day is Monday, so she should say "today."
It appears that there may have been a scene deleted, as the ransom jumps from $2 million to $2.2 million without an explanation. After Barbara gives Ken and Sandy the details of Sam's net worth, Ken calls Sam and says, "We're up to $2 million." He proceeds to list the value of each item so far: $1.2M in equity in his store, $350K in his pension, $45K for the Excalibur, and stock options amounting to $175K. This totals $1,770,000. One flawless, 1-carat diamond would be worth approx. $12,500 in 1986, with 4 of them fetching a sum of $50K. The new total is $1,820,000, $400K short of the $2.2 million figure Sam hands to Ken.
When Earl films the cop and the hooker, Earl talks, groans, and vomits right next to the camera. When the film is played back later, the only soundtrack is the moaning and groaning coming from the hooker in the car.
When Ken, Sandy and Barbara are sitting at the dining room table discussing possible punishments for Sam Stone's infidelity, Barbara sets a glass of milk in front of Ken. In the next shot, it turns into a mug.
During the "Murder?/Police Chief having sex" scene where Earl (Bill Pullman) is filming, Earl is talking, groaning, and barfing right next to the camera. However, when the film is being played back later the only soundtrack is the moaning and groaning coming from the hooker in the car.
When Carol and Earl arrive to video store to watch tape, Carol inserts it into VCR, and police chief Benton's antics appear on all the screens in store. But the VCR's back is facing the camera, and all the output jacks are empty, meaning the VCR isn't connected to anything but the power outlet.