My first station commander at RAF Labuan was an acting Wg Cdr throughout his tour and reverted to sqn ldr at the end. Even the Retired List shows him to be a sqn ldr, rather than the phrase: 'retaining Wg Cdr' which is used if no substantiation took place and was particularly frequently used when there were lots of war substantive chaos around.
I always thought he was hard done by the system - if he was no good he should have been removed.
O-D