Someone please explain why in CM?

[McIvan]

It's hard to say, because its so variable, BUT.....generally a units will retreat like that if they think they have no real chance of hurting the opposition. Possibly the T34 was at an angle, and a 75mm round from the half track at that angle would have had no chance to penetrate. If it wasn't that then I really don't know.

BTW hiding with armour usually doesn't work.....all it means is that the engine is temporarily turned off to stop braodcasting a sound signature. Once an enemy tank comes into view it will spot you just fine in my experience.