And I did not express any opinion on chalav stam.
You wrote:
According to the way the OP described his Rav’s response, this does not seem to be a halachic question per se’. It is muttar to drink/eat chalav stam and the Rav whom he asked did not say that it’s assur for him to do so. As far as I can tell, the issue is not “Is he allowed to eat chalav stam?” but “Should he do so?”