There's a study available online that compares the lubrication properties of additives. Esp with ulsd this is an important consideration.
Don't switch or mix oils brands.
Give him a break the first time, if it happens again...let him have it.
Modern fuel is not as stable chemically as it used to be. Sitting allows components to separate.
A glider with a Cummins gets my vote.
What are some average costs?
Nice truck. I'd love to have a glider someday. Is time running out for those?
It sounds like that driver had other issues and not just whether you were fair or not.