Driving that big old box truck, dude can't see to the side of him very good.
You have to expect shit like that.
Oh believe me, I'm always expecting this kind of stuff... I think I knew he was turning before he did... lol
However... You don't change lanes unless you're sure there's no one there...
But the "worse" part is... he moved to the left lane like 2 seconds before... If he wanted to stay in the middle lane... why do that?