Unfortunately I can't google up any info on the Shuttercam product.

But, as far as I can figure, the photo-finish system at the STC (Rosehill etc.) and presumably many other Australian tracks is as sophisticated as possible.

http://www.stc.com.au/web/Racing/Ra...06/r060301c.htm

Essentially it takes 1000s of digital photos per second of an extremely narrow slit at the finish point and produces a composite.

That's as accurate as anyone would want and presumably instantaneous, so technically there's nothing stopping the TV channels broadcasting the results.