Single person pushbacks are not uncommon especially in the US
Having had some experience with how things are done in the US I cringe when people use that as an excuse.
Read my previous post, true story, the local handling people at JFK insisted on doing the pushback on our (Aussie) Aircraft, single person just the tug driver wearing a headset, pity she had no idea what she was doing, disconnected tug and towbar without talking to the Crew so brakes were not parked when she disconnected, luckily we followed the Aircraft and were able to at least signal the Crew. Our Company then told them that we Engineers would be on all future pushouts.