Man, he's bad. I thought I was Rambo. Yeah, he needs to focus on real problems. By being so ancy, he could miss real problems. He needs to be calm. Being calm will keep others calm. It sounds like he's even upsetting mature divers. I know he could miss problems, because I've been concerned about my gear, but missed the guy who didn't bungee his tank, or didn't connect his inflator hose. If he's concerned about the wrong things at the wrong times, he'll lose sight of real trouble. A person in OOA or panic will be fairly obvious. Also, why doesn't he slow down, and then ask you how much air you have by pointing to HIS guage, if he's concerned about OOA. That is how you prevent it, by watching your air consumption. His instructor may have said something, but he may have not listened.
In class, it's simple, watch students, do what instructor says, let them goof off a little with a close eye on them, be serious when they do something out of hand, and keep calm. When giving tours, be slow, calm, and responsive. I'm often too hands on for really new divers, but my AOW and OW buddies, on my own time, I really treat as buddies more than students (and I'm still learning all of this each day; diving with buddies is more difficult than solo in some respects). There is a difference, and it is taxing on the DM to control other divers. However, I really only control buoyancy, in the up fashion mostly, making sure they don't lose control and go up.
We all make mistakes. I recently made one, and our mistakes are at this point mistakes with how we handle helping other divers. It's a huge learning curve, along with everything else that goes on. I've done my speed diving, good to know my limits, not good to drag others along. I would not buddy dive with him until I made it clear I don't want him touching my gear or me, and that I want him to slow down and act like a buddy. I've had buddies that said, you went WAY too fast for me. Next time you do that, I stop; I listen, now. Also, I follow a lot of the time on dives. Who made him the dive planning authority? What makes him think you're all of a sudden bad divers? I have seen very good OW divers, and really bad ones. The certification does not verify the type of diver a person is. The person verifies that. I've also seen very bad rescue divers.
Conclusion: he needs to relearn buddy skills and calm down or he will incite panic.