When Foggy is speaking to Matt on the phone, there is a man in a yellow plaid shirt behind Foggy as he walks down the street. In shots where he is visible, he is alternately very close behind Foggy and then in the distance.
(at around 7 mins) A criminal racks the slide on a firearm he had just fired. This is pointless, as being a semi-automatic (auto-loader), the pistol would have been left in a loaded, ready to fire state after the previous shot; working the slide should eject the cartridge in the chamber, wasting a shot, and load the next cartridge.
In the confessional scene, the priest is wearing a green stole in the confessional, he should be wearing purple.
When Sergeant Brett Mahoney is informing Foggy about the "homicide" over the phone, the contact list can clearly be seen on Mahoney's phone screen, showing he isn't really in a phone call.
Around 07:30, when Matt is hitting the man on the ground, we can see that he's not even touching him with the fists and that guy's head is going in the opposite direction of Matt's punching trajectory.