That contradicts the experience of basically everyone that's ever towed anything. I'm gonna ignore a bunch of second order variables here but if you come into a turn too hot for the weight of the trailer compared to the tow vehicle the trailer can and will push the rear of the car straight (over-steer). This is exacerbated by long trailer axle spreads and short tongue length (hence why flat towing a car feels the way it does).

Maybe he just drives really conservatively everywhere (wouldn't surprise me since a light foot was key for extending range on early EVs and many people developed that habit) or maybe the trailer is just light enough and being single axle makes it easy to steer enough that the natural tendency of the car to straighten out is greater.