I have only done this in a Custom game on the Rift map:
For example, the mid Inhibitor is down, Super Minions will start to Spawn. If Bot lane (or Top) has its other turrets still up, you can lure them into one of those Inhib turrets, and they will start fighting it, while the turret itself will not be losing any HP. Is this intended?
Are in the inner and outer turrets of those lanes down yet? The minion will attack the inhib turret because it is the nearest enemy, but until the inner/outers are gone the inhib turret is invincible.
So basically, the answer is minions are fucking stupid. If they're attacking a structure they just keep hitting it, whether or not what they're actually doing anything (unless they're attacking the Nexus and the inhibitors respawn; then they just stand around and look all confused)
