When Tony carries Meadow to her room, the number on the door is 22. But the next morning when they leave, it's marked room 20. Earlier, Fred Peters had read on the cleaning lady's list that Meadow was staying in room 20 and Tony in room 21.
When Father Phil is hearing Carmela's confession, in her living room, the stole (the purple strip of material he places around his neck) continually changes throughout the scene from above his collar to beneath his collar.
The gun on the car seat next to Fred Peters is a Ruger .22 target model with a tapered barrel. When he raises the gun in his trailer, the barrel has changed to a heavy cylindrical "bull" barrel. When he steps outside the trailer, it has changed back to a tapered barrel.
When Fred Peters talks with the man and women on following Tony Soprano on the Colby Campus, he describes to them that the car Tony is driving is a gray Town Car, new model. The car is actually a Lincoln Continental not a Town Car.