Corrected entry: When Peter tries to rescue the girl from the tank at the end, he fires several bullets into the glass but it doesn't break. So then he finds an iron bar to hit it with, and the glass shatters. Even if you argue that the bullets must have weakened the glass, anything capable of withstanding the velocity of a bullet would surely need more force than one man can muster in order to shatter it.
Corrected entry: When Carl is in his deep coma, Catherine enters his mind in the lab-room using the special technology. However due to a "power failure," she then has to go across the room to fiddle with some circuit breakers and we assume she isn't in Carl's mind yet, however she then realizes she is already in Carl's mind - but if he has been in a coma for a few days, Carl couldn't possibly know the layout of the lab that he has been taken to, or what Catherine's colleagues look like and what they're wearing or even the red suits he and Catherine are wearing and the fact that they're suspended on wires and are wearing face-cloths, because he was in the coma before any of this happened. If Catherine is in his mind, then all this information we see in his mind isn't possible, as he could never of gathered all this information for him to even imagine it all so accurately - he would have never seen the lab room, and the red suits and Catherine's colleagues. It makes for a good, sudden twist - however it doesn't fit.
Corrected entry: Jennifer Lopez has a button on her suit which enables her to return from within somebody else's mind. It is suggested that by pressing this button in her "hallucination" she is able to press it in real life. However none of the other movements she makes in her dreams is duplicated in the physical world, or else she would never stay on the bed.