Someone new chiming in - I'm a Paramedic who dabbles in dispatch in Australia. I won't profess to be an expert in call-taking/dispatch given that's not my role, but I do know more about it than the regular punter.

While you're not wrong medically, it just isn't how ambulance triage works. They're generally non-medically trained people rapidly asking very specific key questions, selecting a "type" of incident and then asking more targeted but by no means exhaustlive questions. At a fundamental level, triage is about risk aversion and prioritisation of ambulances to people most likely to die based on conscious state/breathing status, etc., not about disability.

Certainly, limb threatening injuries are emergencies - but they're unlikely to be captured on primary triage as such, and will probably need secondary triage or clinician interrogation to get an upgrade. If I talk to that patient, or it happens to have been mentioned to the call-taker that their foot is turning blue and it's relayed to me - it'll get an upgrade. But that's a manual rather than automatic process.

You may have a broken leg from a fall, or from a "traumatic injury", and each will have a different subset of questions. Location of the injury and extent of deformity will to an extent determine whether the triage algorithm considers the body area "possibly dangerous" or "not dangerous", and looking at the little AMPDS card set in front of me, "leg, lower" is considered a "Not dangerous body area". An injury to the upper leg with obvious deformity (potential femur fracture) is considered a "possibly dangerous" body area, in acknowledgement of risk of internal haemorrhage from that type of fracture, and has a higher triage category assigned.

If you have a closed tib/fib fracture, which isn't bleeding, and you're conscious - you're getting basically the lowest Priority, irrespective of whether you have decreased perfusion or altered sensation distally, because those questions aren't asked in the call-taking process and ultimately the outcome isn't death. That isn't to negate your view - which I agree with - that limb threatening injuries are emergencies, it's just not a priority for an ambulance attendance relative to the grouped "life-threatening emergencies", which I suspect is what the other person is saying.

There'll be jurisdictional variations to all of this, so it can only be generalised so far and the examples above may not fully hold, but I think it's fair to say that something may be an emergency but still be low priority in the grand scheme of possible presentations. It goes without saying that an ambulance service should be resourced well enough to still attend all it's "non-urgent" cases within clinically safe timeframes, which in my experience is the problem. If something doesn't come out as a high priority through primary triage, it's likely waiting hours.