That doesn't make sense - RGR is a long dark road with no traffic at that hour. Whereas Kenmore roundabout is brightly lit and has cameras! And those "screams" heard by Will Truter etc along RGR were supposedly eliminated as teenagers skylarking. How could GBC or anyone know that there could be witnesses along RGR, when there would be much more likely to be witnesses at Kenmore?
That doesn't make much sense either - where would you get rid of a body on Brookfield Rd? When you could simply head out along Rafting Ground Road to complete darkness? And why would he need to call for help? Plus, to get to Kholo Creek from Kenmore roundabout one would have to pass the end of NBC's street - why get him to come up to the roundabout? And the chances of NBC being "seen" at the GBC house would be almost zero - it's hard enough to see into the driveway driving past slowly. A chance sighting of NBC outside the house would be almost zero chance.
No - the theory (and that's all it is) of why Kenmore was involved at all only works for me if you assume that GBC (or whoever) was heading somewhere else and changed his mind for some reason. And the theory I posted above would fit that - if NBC had brought OW over, then was helping GBC to take Allison to hospital. But they realized she had died, and NBC didn't want to be involved or GBC didn't want to involve him further, so dropped him off at the roundabout before heading back out along Moggill Rd. That would explain NBC appearing very upset, why he had no car there, why he was even there in the first place, and possibly why the police were timing things at the roundabout - perhaps how long it would take to drive from there to Kholo Ck and back to pick up NBC and take him home....?
To summarize my theory and conjecture:
1. Allison and GBC have a blazing row, with Allison getting severely injured somehow
2. GBC calls NBC via Facetime and says "We've had a fight, Allison is hurt and I need to take her to hospital. Can you or Olivia come over to look after the girls?"
3. NBC drives OW over, OW stays at the GBC house to look after the girls, and NBC decides to go with GBC to the hospital
4. Somewhere up near Kenmore, or just beyond, something happens that makes them realize Allison is dead
5. GBC decides to drop NBC off at the roundabout rather than return home, and rather than involve him in what was to come next
6. GBC drives out along Moggill Rd to Kholo, while NBC sits, very upset, at the bench at Kenmore bus stop - not even thinking about cameras, lights, etc.
7. GBC returns, picks up NBC, and goes home to Brookfield.
8. NBC and OW stay and help clean up the Captiva, signs of the fight, dispose of the tissues that GBC used to dry the scratches, etc
9. Later in the morning, OW takes the girls to school just as the police arrive, following the charade of the phone messages, "gone for a walk" thing. NBC is also still there
The rest we know...
How does that work for a theory?
G'day Doc Watson, How do you do?
I have taken the liberty to take your scenario and amend it slightly. See if this works. Sorry about the ambulance and hospital thoughts, but I can't see that fitting in with a proper murder plan.
1. Allison and GBC have a blazing row. GBC attempts (with the previously thought out plan) to kill her. But she puts up an almighty battle. Unexpected. Allison gets severely injured.
(There is a gap here.)
2. GBC calls NBC via Facetime and says "We've had a fight, Allison is hurt. She might even be dead.
3. NBC drives OW over, OW stays at the GBC house and NBC decides to go with GBC.
4. Somewhere up near Kenmore, or just beyond, something happens that makes them realize Allison is dead
5. GBC decides to drop NBC off at the roundabout rather than return home, and rather than involve him in what was to come next
6. GBC drives out along Moggill Rd to Kholo, while NBC sits, very upset, at the bench at Kenmore bus stop - not even thinking about cameras, lights, etc.
(No that can't be right either as the alleged sighting was 11.30pm, and the Facetime call was 12.30am Need to clarify events of this hour.)
7. GBC returns, picks up NBC, and goes home to Brookfield.
8. NBC and OW stay and help clean up the Captiva, signs of the fight, dispose of the tissues, rags, towels or clothing that GBC used to dry the scratches, etc
9. Later in the morning, OW takes the girls to school just as the police arrive, following the charade of the phone messages, "gone for a walk" thing. NBC is also still there.