I would suggest that the risk of mid-air collision in a well briefed close formation sortie is minimal. The fact that they were mixed types flown by civilian and military crews is irrelevant so long as the guys were competent/current etc. I've no doubt that somebody senior was more than content to initial the auth sheet.
you haven't had to deal with the MAA recently I would guess - they have taken the term risk-averse to a whole new level.
Additionally, when so many military crews are bouncing off currency limits and civilian pilots (ex-mil or not) are unlikely to have anything but the bare minimum close form trg (or any other trg for that matter) paid for, I suspect that competency and currency might be a serious concern.
If you think close formation is safe, well briefed or not, you clearly were never party to the massed approach at Middle Wallop back in the day.
SND - yes, in a choice between the two I think you are correct
