Alan and Matt B's comments make for a very good argument as well why have RIV gear so close to rescue brigades? Plus having over confidence in the ability of RIV gear can be a dangerous path to follow, imagine that not calling a 2nd rescue appliance to 2 confirmed entrapments, if it went wrong I'd hate to think of the consequences!
RIV gear is well and good enough for non - complex type entrapments, and is well worthwhile in intermittent brigades where the surrounding areas still have a full RCR kit.
Being CFS, there is no certainty EVER that a brigade will necessarily have a crew together, and not default. It is better to at least have someone with the tools to begin procedures without having to wait for a rescue resource from further away. Bridgewater for one is in a very useful space, as Stirling certainly default often enough, and after waiting for the default, it is another 5 - 7 minutes before Mount Barker or Burnside / Glen Osmond get a run. Then the travel time, not something you'd be fairly concerned about if you were the poor bugger in the car just wanting someone to get you out.
Pixie, I tend to disagree about the MFS and more experience. Like all services, there are a hell of a lot of nuffers out there, and yes, they work every day in a firefighting capacity, but unless they're a country fringe brigade, there is probably little opportunity for them to practice extrication, due to the lack of areas where such high mechanisms required for entrapment can occur in the metropolitan setting. SES were looking into new stabilization measures such as STABFAST before many in MFS knew what they were, agreeing with Darren. Horses for Courses.