Regard a Mere Mad Rager - S2-E19
Continuity mistake: When Reade is in Weller's office, his face is still pretty bruised, especially around his left eye and cheek, from the drug dealers beating him. When he's talking to Zapata outside of Weller's office, his face isn't as bruised up.
Continuity mistake: When Shepherd spots Jane and Kurt on the security camera, they're both walking past a set of doors. Two shots later, they walk past the same set of doors again.