Near the end they are loading girls into a tractor trailer. The girls go up the ramp and then the doors are shut and the ramp is removed. A few moments later the "good guys" are at the back of the trailer. "Open the doors" one says. The other does and the girls start coming down the ramp. But there were no ramps a few moments before. We do not see them being put back.
The tiny cylinder implanted in the girl's hand is too small to be a GPS tracking device. It resembles a RFID chip. The latest RFID technology can be read at about 50 feet maximum. A functional GPS device like that you would attach to a bicycle or pet collar is at least 3/4 inch x 4 inches.