The reversing vehicle has the greater duty of care, in other words must give way to everything.
Him performing a Uturn in a carpark is not illegal, but him hitting you might be considered negligence.
All traffic incidents need to be reported, more to cover you're own ass than anything because the other bloke might go later and say your tore off his bumper.
Also relying on your sensor is pretty stupid.
Likely scenario, both be hit with a Neg driving charge.
Not sure, bike goes in for its major open heart surgery soon, but it still pulls strong throughout its rev range.
I do basic servicing myself, if i need something tinkered with (brake pins need sanding, forks need servicing) i drop in to see my mechy (if you are near campbelltown, hit up...