His career did indeed start then, but that meant he got his formulative training years when 'Sir Joh's corrupt system was still at its peak...
(in fact, there still IS a lot of 'low level' corruption going on in the Qld police force even today, as the locals will tell you....)
They needed (but didn't get) a Royal Commission inquiry into them same as NSW got- the inquiries into the Qld cops really only touched lightly into the deep seated corruption at the grass roots level at the time (and still exists only mildly reduced even today)