Actually no man. If you will simply run straight without any orders the AI will blast it off. And this issue is not present in ArmA2 1.11
It's not the location. It's no different anywhere else. AI has a lot of chances to fire at Shilka but it does not take the shot. In fact it's the AI that detects it first. So he sees it. He knows where it is.
Solution should be simple. Vehicle in sight? Blast it. There will be no time to look for a good position if it faces you.