It's pretty obvious that TWI is using the standard UT3 tank AI code, maybe with a few minor tweaks, but they haven't fixed it.
It was like this in UT3 aswell, the Tank AI both wallhacked (tracking players through not just walls, but entire buildings) and aimbots, they hit with pinpoint precision.
It's allways been terrible code, you see a tank, you run around a building trying to come at it from it's flanks, but just as you round the corner you hear the tank fire and you walk right into the shell, the thing just tracked you through the walls, and they don't miss.
But atleast in UT3, the tanks were as weak as all the other weapons, you could survive a few hits, so you could actually kill them if you had a powerup and the AVRIL ainti-tank weapon to hit it with. In Ro2 you just die instantly from a perfect and instant headshot, making it even more broken than UT3 was.
A lot needs to be done about this code, the AI apparently knows that there are walls, because it is beeing told not to fire untill you are visible (or rather, it will fire just before you are, it can see you are moving out of the cover and leads the target, shooting just before you peak out). But it is not told to ignore targets behind walls, it tracks them and anticipates their movements, when it should actually be told that it is not allowed to be aware of thease targets, that they should be ignored entirely untill visisble.
For that matter, i don't even think they are restricted to seeing targets that are in their field of view (be they behind cover or exposed, since as we've established, they see through walls), i'm quite certain they have a full 360 degree field of view, that they know where you are regardless of if they are looking in your direction or not.
The UT3 ones certainly did, even if you managed to get behind a tank because it was too buissy shooting at targets infront of it, it would just turn it's turret and blast you the moment it was done with the targets infront, it knew you where there, it just calculated that you where the lesser risk and that you could wait. That obviously needs to be solved too.
And the accuracy needs to be nerfed, by a lot, thease bastards just don't miss, they will often fire just one or at most 2 shots, because that's all it takes, insta death every time.
The AI should perform worse than a human player would, that beeing the whole incentive to multicrew tanks, they work if one manned, but they will be even better if you get a few people in there that know how to use them.
That's not the case now though, having the AI do the work means you have hyper vigilant aimbottitng wallhackers doing the work, so they are better in every way.