I had snipers out in the map and attacked a mortar team with a stug nearby. The Stug turned to go after the sniper as my sniper vanished. Apparently the Stug can see hiden snipers and chased mine all over the map until the stug finally ran him over. YAY AI!!!
After the shot on the mortar team the sniper was never revealed. The tank just fallowed him around through turns and ran him down.