Continuity mistake: When Harry Mitchell is at Leo's club with Doreen, he takes a Polaroid of her. When she asks him how it came out and he tells her it's a little dark, he's actually looking at the picture upside down. We then cut back to Doreen then back to Harry, only this time he's holding the same picture the right way up. Also, during the same scene, Doreen's suspender belt starts off attached to her stockings, then it's unattached, then attached, before we see her unattaching it.
Continuity mistake: After picking up the package at the Mets game, we see Bobby get in the car. From outside the driver's window, it's clear a mirror is mounted on the door. But as the crew is driving down the road, about to open the package, there's no sign of the mirror. It can't be lowered enough to hide in these shots. It has been removed for this scene.
Continuity mistake: When Bobby forces Mitchell to drive to the warehouse, exterior views of the building show it is about 4 stories tall, with garage doors on the first floor and large windows on the 2nd and 4th levels (unless every level is very high, in which case the windows are on the 2nd and 3rd levels) and the roof is an A-frame. The nearer attached portion is 1 level with a flat roof (note the added structure standing on that flat roof). But inside, we see the A-frame ceiling is no more than 2nd-level high and we're still on level one. No 2nd or 3rd floors at all.
Plot hole: Throughout the film, Mitchell's main reason for not contacting police is that his affair and his mistress' murder would become public, derailing his wife's election and thus destroying "the one thing she built for herself". Seems odd that part of his plan is to rig his own car with explosives (from his own company), give it to the lead bad guy, then blow him and the car up on a public bridge. Certainly not a 'character mistake' as the tone of the film's ending is that, somehow, he has won, when he's failed in spectacular fashion to keep it all quiet- and his wife's been drugged, beaten, raped, and her career is over, while he's going to jail for murder.