This is particular true when it comes to the device's desire to detect changes in direction. It could be argued that, depending on the application, the more "sensitive" will detect minute changes in direction of a drag, and express those by anticipating that the desired direction of wipe is intended to go in the direction the finger heads. After all, this involves some type of algorithm to determine what smaller spot on the larger finger pad is intended by the user as the "touch."
So one could just as easily argue, based on the limited information we have, that the Android screens more accurately picked up and expressed a minute change in direction by the finger, while the iPhone didn't.
It seems like it would be software-driven. The finger pad is bigger than that draw spot, and it is moving.