You sound like a very twitter and bisted person F4TCT.
Why would anyone ask why did he leave the RAF? They already know. Doesn't everyone? He did a full tour on SAR and his time was up. He could have stayed, he could have disappeared into the royal gloop or he could have told his advisers that he wasn't ready to hang his goggles up yet and wished to try something new. We have a saying in the mil brother: RHIP.
If you've got it............flaunt it.
He's eminently capable from a practical perspective. He wasn't from a paper perspective (as all mil pilots aren't when they turn to civvy street) but he has now completed what ALL abo's in civvy street have done - his CPL exams.
Cheer up - it could be worse he could have gone FW!