"Swim-through" okay for open water divers?

[Cthippo]

Does the geo-dome at Mukilteo count as a swim through, because I was doing that during my OW training. With a camera on my last training dive. Still didn't die.

Then you had no business offering to buddy up with him. Lots of people have a card that says "Rescue Diver" and it's not impressive. It would have been more impressive if you actually acted like a proper buddy. Not just keeping an eye on him and essentially letting him fend for himself.
This kind of stuff is why new divers say screw it after a few dives and find another hobby.
It's not being a baby sitter sticking close to a new diver. It's being a decent person.
With the attitude you have, you should get a solo cert and let people who are willing to really help out new divers be the buddy.

I would want to have a conversation with a buddy on expectations, but even as a new diver I don't want someone hanging right net to me. If I have a problem it is just that, my problem and I expect to solve it myself while they stay close enough to assist if necessary, but to not be involved unless asked.