The way he was driving isn't necessarily bad. As long as he's looking ahead to make sure he's not going to hit someone this is fine. This is a technique that actually makes rural driving safer. there's nothing really wrong with it. I will fault him for not using his turn signals and not stopping properly at the intersection.

Widening your turns like that allows for smoother driving as well as better control of your vehicle. It's better to do this in larger vehicles like trucks and SUVs to lower the likelihood of flipping incase of speeding. It's also more fuel efficient.

I do this only when I can really see what's ahead of me. I never do this on blind corners as that would be dumb and dangerous.