It's beginning to look like a conundrum inside of an enigma inside of a riddle.
Yes, Tigre, he was a Luftwaffe officer. But could there have been a Flak officer of the Heer coincidentally named von Minden in the campaign, too? We don't know with certainty that Rudolf von Minden participated in the campaign. All we know with certainty is that there was a Luftwaffe Flak officer by that name.
A Luftwaffe Major would absolutely NOT have commanded a Heeres-Flak-Abt. We can rule that one out.
Dr. Leo is a human being (and a good one, at that). All human beings are fallible. Dr. Leo's information could be wrong. It happens to all of us.
......could not an Army Flak officer be assigned an Air Force Flak HQ as liaison or something like that?
Yes, Tom, the Wehrmacht made wide use of Verbindungsoffiziere whereby a Luftwaffe officer was attached as liaison to a Heeres- command and vice versa. So, theoretically, Luftwaffe Maj. Rudolf von Minden could have been attached to Heeres-Flak-Regimentsstab 11 or to any of its three Abteilungen.
We certainly are not at the bottom of this by any means, and it may ultimately take some research into documents that none of us have.
--Lorenz