This certainly seems like one of those accidents where there would have been nothing to see had the Swiss Cheese holes not lined up: if they'd waited even 30 seconds to get eyes on the Pawnee they might have got a scare but nothing else.

It points out to me the importance of an "entering and rolling" call.. which perhaps might have alerted the Pawnee to look left? ..but then maybe they did and he was occupied with the go-around??

Instructor: "Why the %$#%$ didn't you ... ?!?"
Student: "'Cause I'm an effing student, that's why!"

No winners here. :(

All accidents are ones where there would be nothing to see here if the holes in the Swiss cheese hadn’t lined up…

Also not commencing the crosswind turn before the intersection.

I strongly suspect the only reason Dave started to turn was he suddenly saw or realised the Pawnee was coming. When I flew with him just before the accident, he gave a very detailed brief in the event of an engine failure. This plan was straight ahead to one of the only clear patches surrounded by heavy timber on the extended centreline.

To my way of thinking the only cure is for everyone to use the same runway and that is the one most favourable to the wind direction. I know airmanship is no longer fashionable but that is what we always did in the past and it seemed to work.

Commencing the turn, a pilot creates a blind spot in the opposite direction and excludes themselves from the see-be seen, especially in high wing aircraft. I am not referring to any person, this is my personal takeway.

Whilst I generally agree with that and am not meaning to dismiss your comment, there can be (what I belive are valid) reasons for not doing this at times.
The tug would have been towing a cable, so avoiding using the runway that the other aircraft are operating on, may have been one of these reasons.

But we don't know if this call was made or not, given that recordings from Caloundra won't "hear" any ground traffic at Caboolture. Given Dave's professionalism (that I'd seen), I suspect it was.

True, but by this stage he'd obviously seen the Pawnee and was trying to avoid it. Nobody, just nobody, would otherwise attempt a turn before the runway intersection (it's a run of 800m)..

You are thinking 2 dimensional, aircraft move in 3. The blind spots are always there and in the circuit, especially in this scenario the threats are coming from not only level to, but above and below. The turn does not create a blind spot where the wing is, the blind spot is always there, which is why old teaching had clearing maneuvers to check blind spots periodically, like lowering the nose during long climbs, or lifting the wings during lookout prior to turns. Also remember there's also a lot of other things blocking the view, passengers head, how big the windows are, support pillars, engines in multis etc etc....

This is what the rules tell you to do, anyone on the most into wind has priority. You are not allowed to proceed to land if the runway you are using is occupied, you are not allowed to take-off if the runway is occupied, which includes aircraft using intersecting strips. LAHSO is not a thing outside approved controlled airports with strict rules. The landing aircraft should not have announced that they would hold short, there is no way you can guarantee this until you are stopped short of the intersection. In addition the pilot departing should not accept an aircraft offering to 'hold short' while they depart, until that aircraft has stopped short of the intersection, or passed through and so on. Generally you will state that you will let the other aircraft know 'once' you are holding short so that they can depart.

A rolling call after a long backtrack, or something to that effect is essential. There is no mention of the Cessna that taxied across the runway making a entering/crossing call, which is also essential. Again use of words such as 'active' runway, changes a lot of how somebody views whether the calls are necessary. OCTA it is essential you make a call entering, backtracking or crossing ANY runway, the only time you might not call 'crossing' is when already occupying a runway that you are using to roll on during landing and take-off. These rules are as opposed to a controlled airport where 'active' runways may be treated differently to non-active ones.

​​​​​​​What, so continue straight on, into a collision?