It's entirely likely that Redbook has made a mistake there. My 2009 STX doesn't have EBD, it does have ABS. Rear diff is LS, front is open (and weak as piss, don't lift a wheel in 4WD with your foot on throttle).
EBD was not considered necessary for a tradie's ute back then. Even in 2009 for mine which was then the "top of the range" they couldn't even scratch together a pair of friggin' disc brakes for the rear, I've got shitty drums. Try loading up with tools and stuff and reversing down a hill some time.
With Mishitibus leading the way in the ANCAP rating war, Nissan are lifting their game and putting in stability control, more airbags etc etc. You might find EBD in a 2012/13 model, but I doubt it's in anything much earlier unless it came from Europe, where the 2009 STX even had climate control. Too much bells and whistles for us stupid Australians who don't know what a Celsius scale is, so they never gave it to us.
Oh, and the pisser about the stability control: when you NEED to turn it off, it doesn't turn all the way off. Ask a 550 owner that's taken theirs bush, it's not perfect.