As Tom is sitting on the bed thinking of his wife he reaches under the bed for a box and the clock in the background reads 11:40. We then see a close up of Tom smelling her perfume and the clock now reads 11:38.
Tom Cutler and Ann Norcut meet with Arlo Grange (the police coroner?) for Ann to identify her husband's body. When Vargas shows up, Tom uses the ruse that he just happened to be there and was going to go to lunch with Arlo as soon as Arlo was free. According to the clock on the wall, it was 5:30; whether a.m. or p.m., it was nowhere near time for lunch.
Towards the end of the film when Tom (Samuel Jackson) rushes home after discovering that Eddie is there with Rose, Tom smashes Eddies drink which we see shatter on the kitchen cupboard. However, when the shot changes, Eddie is still holding the same glass of drink.
At the end, Ed Harris is pointing his gun at Samuel Jackson with the trigger in the rearward position, something that only happens when the double action/single action Beretta is cocked. The trigger should be at rest, in the forward position. When agitated, Ed cocks the hammer and we see that the trigger is still in the rearward position. Only at cocking should the trigger have gone from forward position to rear position.
When Tom Cutler goes to the crime scene for the first time, the address in the clipboard shows 1257 Ridgewood Way but when Ann Norcut visits his office, she mentions Ridgecrest Lane as the address that Cutler was looking for. (That is the address he gives her when he realizes something strange is going on at that residence.)
As Detective Eddie Lorenzo stands waving his gun, a short while after he discovered that he had a piece of glass in his left arm, the blood disappears as the camera changes angle and although the audience doesn't see his entire arm at that particular angle, at the volume he was bleeding, his entire shirt would have been dripping with blood.