I just want to chime in to say, the mod team has considered this option. We might go back to closing the DIR forum some day, but that has downsides too. The current thinking is that we will try our best to enforce the rule against non-DIR answers to DIR questions, which I think should help in cases like this one.
But, most of the mod team is not trained by DIR agencies. And, the ones who are, would often like to participate in the threads. ScubaBoard has a strong convention of the mod team not moderating threads they are in -- obviously, the chance for a conflict of interest is much higher there, so we try to avoid it. This leaves us in a predicament where the mods who best informed about what a DIR answer is, are the ones who are opting out of mod duties within the DIR forum.
I would encourage you to hit the report button if you see posts that violate the rules. This is the best way to let mods such as myself who aren't trained in DIR, to keep the DIR forum free of the noise of incorrect answers. I posted an updated DIR forum
rules thread a few weeks ago, you might have a look. If you have feedback on that rules thread, send me a DM and we can discuss it.