Gertrude/Tmmorris;
You are both right, the difficult bit is pinning down who he was and where from to be able to file on him. It was a monumentally silly thing to do, and I doubt he saw us in his six o'clock at very close followed by a full power pull up over him climbing like a dingbat. I saw enough to realise he was a 182 and that was it.
If I had caught him wing tip to wing tip I doubt I would have felt more than a thump and seen some witness marks on the winglet after landing, as it was he was about to come through the windscreen at around 1700' in solid cloud, I got a view of about two seconds as I hit the TOGA buttons and pulled the stick back. I had no idea my heart rate could go so high!
Basically it was poor airmanship, if he had spoken ATC they would have happily taken him for a practise ILS and we could have ensured separation and that is what ATC is really all about, keeping us apart in the air, it is so much easier for them to do it if we talk early and arrange the ATC/Pilot "contract" that they discuss so much in MATS part one.
Just my thoughts.
SND