Ok, thanks, that's what I thought. I don't know much about the event either, and can't offhand recall mention of any branch of the Wehrmacht other than Heer being involved.
What got my interest was that dad had mentioned that he was there that day, so the most I've done since is a little online research.
I found an interesting article with Otto Ernst Remer's personal account of his role in the event, part of which corroborates exactly what my father told me:http://library.flawlesslogic.com/remer.htm
Here's the pertinent excerpt from the Remer article:
"Due to the prevailing uncertainty and because of misunderstanding -- some thought that the guard regiments sealing off its designated area meant that it had mutinied -- on two occasions my regiment came within a hair's breadth of being fired on by other units. At the Fehrbelliner Platz an armored brigade had assembled at the order of the conspirators, but an order radioed by Lt. General Guderian removed it from the conspirators' control.
Thereafter this unit undertook reconnaissance and mistakenly concluded that the guard regiment "Grossdeutschland" was on the side of the conspirators and had apprehended Reich Minister Goebbels. Several of the brigade's tanks advanced tentatively, and bloodshed could have been a near thing had I not intervened personally to clear up the confusion.
The same thing happened in front of the Bendlerblock, the Headquarters of the Commander of the Replacement Army, when a Panzergrenadier company tried to take over from my guard, which had been authorized by the Fuhrer. The energetic intervention of officers from my regiment made possible a clarification at the last moment and prevented German soldiers from firing on each other. Here too the question "Hitler -- with him or against him?" proved decisive."
Dad recalls that while at the army weapons school, one day out of the blue and under highly emergent conditions, they were handed combat gear and automatic weapons "the likes of which we wished we'd had in Russia". All they knew was that they were responding to an emergency somewhere in Berlin. Allied bombing raids were already taking their toll on the city and the civilian population, so firefighter or rescue duty wasn't out of the question at that point. No military vehicles were available to them, so they had to commandeer buses, trucks, streetcars, whatever was available at the time to get to wherever they were ordered to go as fast as possible.
Once they got there, he recalls watching his commanding officer not far up ahead, engaged in a very heated discussion with a commander of the unit which was already in place. Said they were prepared to fire on the other German unit there, but the situation was defused before it got to that point.
As a result, his unit wound up standing guard around some building complex, orders were to let no one in and no one out. The guards cordoning off the complex couldn't have been posted very close together, because at some point dad saw someone sneaking out of a back door of the building he was standing 'guard' behind. The individual was clearly trying to make an inconspicuous exit from the building, and in the process, happened to be headed directly towards where my father was standing. As the 'escapee' moved closer, dad saw that he was an elderly gentleman in a Kriegsmarine uniform of considerable rank. Having already had enough of the military and of his year in Russia and of the politics, all dad felt he was obliged to do at that point was to give his superior officer a simple salute as the old man passed by