The product is supposed to protect against that problem:
Safety?
To protect people and equipment, the Quick 220 Power Tap's automatic safety interlock blocks all power to the 220/240 volt outlet until electrical connections are complete and correct. Should one of the cords become disconnected or loose power, all powered connections to the 220/240 volt outlet are immediately and simultaneously disconnected, including the exposed power cord. Internal test circuits are employed to assure wiring, polarity, and output voltage are correct.