Other: At the start of the film where Detective Dooley and Jerry-Lee are getting ready for work, we see Dooley climbing out of the shower, but in the reflection in the mirror behind him, we see him emerging and can clearly see his under-pants which are bone-dry.
Great sites
Mistakes
At the end when it shows Dooley and Jerry-Lee filming the exercise video, Dooley has a plaster on his head in the exact place he had one when it showed Dooley trying to get Jerry-Lee to jump off the roof. See more...
K-911 mistakes
Revealing: When Dooley talks about his car to his boss, there is a woman in the ambulance behind him writing on some paper. If you look closely you can see that she is just moving her hand and not actually writing.
Visible crew/equipment: When Phil gets the Bazooka out of the trailer, look carefully and you can two head shadows in the trailer. One for Phil and one for the cameraman.