Interesting thread - I would like to know how A/G radio operators & AFISOs, are allowed by the CAA to sign off these forms. Yes, many have a wealth of aviation experience and may recognise poor airmanship, but for these people to have a possibly catastrophic affect on some wannabes career, shouldnt they have some formal professional qualification.
Perhaps what I am suggesting is that QXC flights should only be between units equipped with full ATC, where at least the people who sign the form have professional accountability for their verdict?