It does seem counterintuitive as the rth point is stored in the copter (so it can rth if disconnected from the rc), but perhaps restarting the app and replugging the usb forces an rth point reset in the copter. When I've had app crashes I have not seen rth point resets.
This brings up a question, though. Does the rth point include altitude data, or just lat/lon? In the OP's case, had he hit rth would it have gone to the new point, descended to 145 feet and hovered there? Or would it have gone to the point and descended until on the ground? I suspect the latter, but does anyone know for sure?
From what I understand about RTH, it doesn't force a descent ... only an ascent if below failsafe altitude at time of RTH activation.