Sebastian, who stood in for Paris during the earlier magic performance was never seen again after he peeled off the Paris "mask" in the box truck, or present at the end as the IMF prepares to depart.
The block of cement Barney cuts out of the cell wall would have been too thick to simply tip it out of the way as is shown. It would also have been far too heavy for him to lift easily.
When Paris and Tracey are being detained after the bomb blast, two guards are standing directly behind each of them. But neither guard notices the overt remote control device in Paris' right hand, which he uses to summon the falcon to distract the guards.
After Phelps activates the briefcase film illusion of him continuing the interrogation of Stephan in the prison, it was never explained how that footage of him and Stephan was obtained.
At the end of this episode "The Falcon", they forget the falcon.