I don't know. Often it seems randomly based if I move an infantry NEXT to a tank but still in a forest or house. Often the tank wakes up and senses me there then fires.Tanks cannot see infantry or AT guns in terrain - ever.
It is possible that there was a hidden enemy scout near by that I was not aware of, but I'm not too sure on that.
To be honest, I'm not 100% on some things. If I SNEAK into a closed terrain, I get the cover of that terrain for that turn, but if I just walk normally into that terrain, I get no cover for that terrain for that turn?



