@Angelo **********
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.