I agree with your argument, however I think it would have been much better presented without the word DIR. Lack of DIR does not a bad buddy make, and DIR has little to do with UW photography IMO.
I dove last Summer with my Cuz who has been diving since the early 70's (never heard of DIR BTW). I am a relatively new diver. We did a lot of diving together, and both had cameras. We were within 10 feet of each other most always, and while we were both taking photo's we worked out very well as a buddy team and we remained tight.
This has nothing to do with DIR training, but rather the decision to stay together regardless of vis (which was great), photo OPS, or personal desire to go off to see soemthing. If I wanted to go somewhere, I'd wait until she was done with a shot, grab her attention, and we would both go.
This is what being a buddy is about, and while I do think that having a camera can be a bit distracting, if she had gone OOA, I was never more than a few feet away, and a quick pull of the fin, or tap on the shoulder, and the OOA sign would have prompted air exchange.