Rob, rotate speed is higher than V1 so reject at rotate = off the end of the runway and likely death/fire/paperwork etc.
Not familiar with the 737 but on my aircraft the stab is set using CoG, weight and flap setting. If this setting is off then extra (or less) control input is required and trim accordingly.
I am doubtful that the pilots would have noticed before rotation so fail to see how a high speed reject may be a consequence. The acceleration may have been faster than anticipated but thanks to flex/derate, every takeoff is different and would be very hard to pick.