Courtesy costs nothing. Where do you think this dump truck is coming from?
I am picturing a t intersection of normal 2 lane roads. He is on your right wanting to turn left. You want to turn left to be going in the same direction he is now going.
Onviously if a dump truck is coming from your left you would be wise not to pull out, no matter who waves.
So I guess your point is I was cranky and mean to the kindly old gentleman.
Tuff crap.
I’m still alive!