For all intents and purposes, you're probably right.
I think you might get away with asking politely for a second opinion if the reason for refusal is in question, but a second officer might tend to just back up the original.
In this case, the officer voluntarily called for a supervisor and, although I don't speak enough Thai to understand the exchange, the supervisor appeared to explain the visa to the io and nodded to me to reassure me my visa was valid and there was no problem.
The original io didn't ask any further questions and just stamped me through.
Since it was the second time they asked, I had my condo lease scanned on my phone and showed that. It seemed to spark more suspicion, rather than help.
I didn't see it as a loophole. I was already traveling when the DTV launched, so used the consulate closest to me. Phnom Penh allows it; they don't require resident status.
As a "digital nomad" (which is whom, I understand, my flavour of the visa is for), being physically present in my "home" country is pretty rare. If this is a requirement, I didn't understand that when I applied, and tbh am still not sure it makes sense for this particular kind of visa.
I do respect the law. I was in Cambodia 16 days and thought it'd be enough time to get the DTV approved, otherwise I'd have had to wait until this recent trip back to Australia to do it. After a couple of delays on my side the DTV was approved on the same day I returned to Thailand. I thought it would be as valid as any other visa, but now I can see how it might look weird to an immigration agent.