It dawned on me to track down online if the network is commercial or cable, and it's commercial. In fact, its Wikipedia page explains exactly what we need to know:
'Movies screen with "limited and brief commercial breaks".'
So, as suspected, that explains the extra 22 minutes.
It's still odd, though, that they list the time for the films they run with the commercials added rather than listing a film's own running time. Networks here in the US always list a film's own running time no matter how long the time period may last for showing it. But, of course, Australia is not here...