It's true, dirty tricks are used all the time in war, at least in this case it was used against combat forces and not civilians. Let's bear in mind however that WWII, especially in the east, was a totally different and much more brutal affair than the "clean" and sanitized version we have today.
For example, i don't know how i would react if an opposing military force had declared all the people in my country as only being suitable for slave labor and extinction and set out to accomplish just that. Eventually, this is the vicious circle of human nature...the more brutality one receives, the more of it he's ready to dish out. In this sense we don't differ much from dogs
Going silent on the attack run is practiced today as well. My country has a mix of professional and conscript soldiers (conscripts are the majority) and i served for a year as an AA gunner in the air force. When we were training in boot camp we had about 11 roll-calls/assemblies during the day for various reasons. If it was time to eat we assembled and marched to the mess hall, if it was time for the guard duty briefing we assembled and marched to the guard control center and so on. During our training there were frequent visits by F-16 block 50/52 units and during one of those times i actually, truly realized how powerless a foot soldier is against the air force. We were assembled and about to march out, when i suddenly caught a silhouette with my peripheral vision. Turning my eyes to see better, i could clearly make out a F-16 making a mock attack run against our assembled company. It was less than a kilometer away and that thing was freaking silent as a sleeping baby!
I suppose they used to come in low, pop up a little further away from us and then dove in with the engine at idle and you couldn't hear a thing until he was less than 500m from us, by which time he would already have dropped whatever he wanted on our heads. Scary
