an homage to The Texas Chainsaw Massacre?
Clearly homage to the end of the original Saw where John Kramer slammed the door closed.
Didn't remember that...Just pictured when Leatherface would always slam that sideways steel door....
It's the same thing as TCM you are right. But the last shot in the first saw film was the same last shot as in this one.
You could say the original SAW made a nod to TCM!