I've heard today from a mate of mine that he was the only person out of 16 to pass his AIB a couple of months ago, and another acquaintance of mine from my Culdrose POAC course had everyone on his board fail as well. The former is off to Dartmouth (Warfare Occifer) in a couple of weeks, the intake consisting of only 60-70 cadets, rather than the usual 100+.
It seems that either nobody has been of the required standard of late, or that the RN are seriously cutting back on officer entry at the moment.