Yes, anyone ever in the military, including and especially Blumenthal, knows the distinction and the overwhelming majority don’t make the repeated slip of the tongue he has admittedly made. In my book he’s a liar!
Technically I was enlisted in the Reserves (in ROTC) during the last years of Vietnam and I have never, ever said I am a Vietnam vet.
There was a UT Republican after World War II who lied about his war record and was booted out of Congress. I forget the details, but I believe his name was “Stringfellow”.