 What would have happened if Allen's blaster had not run out of charge?
Without pausing to think, Alan leaped back, and fell sprawling over a bush just as one of the robots rolled silently up from the right, lowering its blaster barrel to aim directly at his head. With an awkward jerk the robot swung around and fired its blaster, completely dissolving the lower half of the cat creature which had clung across the barrel. The metal killers, tuned to blast any living flesh, would murder them the instant they stepped from the ship! Apparently the robot hadn't sensed him yet, but Alan didn't know what the effective range of its pickup devices was. Behind, the robot crashed imperturbably after him, lighting the night with fitful blaster flashes as some winged or legged life came within its range.
 He would still have hit the switch, ending the story the same way.
 He would still have hit the switch, ending the story the same way.  He would have been able to shoot the switch from where he stood instead of having to make a run for it.  He would have accidentally cut off communication with other ships.  He would have been able to shoot down the robots and not need to hit the switch.