Amusingly, I've often found myself scratching my head as the AI randomly shells areas that are nowhere NEAR my troops.
And that seems to happen far, far more often than the AI pinpointing one of my troop concentrations that are clearly out of LOS. Like narwan, I have played this game a LOT too, and I have never seen the problem that BigJim is stating. Has the AI gotten lucky from time to time and blasted my men out of LOS? Sure, but more often than not, I see the opposite as well.