I recently gained a Debris field full of crystals around one of my planets, but I don't remember there ever being a debris field there, and I have no combat reports. The only thing that I can think of that might have caused it was a failed espionage.

So my question is this, does it state in the reports of when one your planets is scouted that the espionage probes were shot down, or is it the regular message of when they are just detected. Also, do they leave any debris, as there was only crystals in the field.

Yes, a failed probe will leave 300 Crystal in debris when it is destroyed, as far as i know that is the only way to tell if a spy mission against you has failed.

-Istalris-