Or that if they were deployed, they were cancelled? Having recently done several rejected landings (in the sim I hasten to add), you are not far off flying speed and it doesn’t take that much time and distance to become airborne again. If you had touched down, autobrakes kicked in, selected reverse then realised it wasn’t working and tried to unravel all that you are in a whole different ballgame.
I think it's reasonable to assume that if an overrun was looking likely and you were still trying to stop, you would be bending the TRs backwards all the way to the end of the runway and beyond. As pointed out above, thrust levers out of idle means no reverse.