Character mistake: As Reddington sets up the blood transfer between himself and Ressler he inserts the intravenous line in Ressler's arm first and then in his own arm. This way the remaining air inside the line gets into the recipient's body and could very well kill him. Judging the expert way he handles the set up he should know to first insert the IV in his own arm, let the line fill with blood and then insert the IV in Ressler's arm.
Suggested correction: That amount of air would probably not cause any problem. It actually takes quite a lot of air to cause any issue.
Other mistake: Elizabeth picks up a stuffed bunny which supposedly was from her childhood. The bunny has burns on it after being in a fire. You can see 2 plastic tag fasteners attached to the bunny, which wouldn't have survived the fire.
Suggested correction: Later we see in the flashback that Liz was holding the bunny. It only got singed as she was escaping. It wasn't "in" the fire.
