While building an outer wall to seal off new territory for expansion, I noticed that upon deconstructing large rocks that also contain coal, any Repair Turrets within range would try to send some kind of beam out to the coal that fell to the ground. This would remove the deconstruct marking upon them and result in my own construction bots not picking them up.

Using my Deconstruction Planner to mark the fallen coal for pickup results in any Repair Turrets in range repeating this very strange behavior.

In the end, I wind up have to run over and manually picking up all coal off of the ground.