How to Handle a Vet?

[tarheelcoach]

I just got into officiating after coaching for years (I still coach as well), and during our pre-season games the vet I was working with was still following old rules instead of the new ones. I know because I've coached at that level before, and because I spent the day before studying the new rules.
But I went along with him because he was the lead official, I was told to 'learn from him'.

What's the best way to approach your partner when you know he is wrong?

Also, a similar question - During a game I was coaching this situation came up and started thinking like an official and wasn't sure how I would handle it -
One of my players drove to the lane and slammed into the defender (an obvious charge I'll admit!) The lead called nothing, but after a moment, the trail blew his whistle and called the charge. Should the trail have made this call even though technically it wasn't his area?