Replay: https://replay.faforever.com/14230328
I have seen this in game quite a few times, where sometimes units waste all their firepower at an unbuilt Aeon PD. Possibly also other structures.
It was easy to reproduce.
It seems the Aeon PD is underneath the ground, units target it and hit the ground instead.
It does NOT affect UEF, Cybran or Seraphim PD. Also tested this in the same replay.