not sure where truefaith get's his info from, but unless he is directly involved with the recruitment of cadets in SQ, the age 26 rule is not hard and fast. (no offence to truefaith)
from SQ HR (the horse's mouth), as explained during the interview: as long as MINDEF clears SQ to take you, they can take you as a cadet. There's a lot of rumours as to what age you are automatically released and what not, but that's the simplest fact. MINDEF says they don't need you, SQ can have their pick.