When Amahle is in the car driving Cole and it cuts between close-ups of her and Cole; the speed of her driving indicated from watching the outside environment from the driver's window is different than the speed shown from the passenger side window.
When you first see Cole he is sitting down outside the principal's office with his hands handcuffed behind him and by himself with no authority figure with him. Additionally, he was not tethered to a pole or anything. This is highly unusual. A handcuffed student would not be left outside of a room unintended, especially in a situation where they can easily get up and leave.
A drive from Detroit to Philadelphia is approximately 9 hours non-stop. It wouldn't be realistic for Cole's mom Amahle to make such a long drive by herself without stopping, and especially departing directly from school with a non-cooperative male teen son.