I'm sure it's just a matter of flicking a switch to activate another program, but my first thought was "shouldn't it react by backing away from the attempt if it detects someone trying their darnest to prevent it from opening the door?" Apparently my instinctual scenarios for the robot's use are peaceful (working at a hazardous environment) and not confrontational (such as thwarting a robbery, where you wouldn't want it to yield to human opposition).