My theory is if in doubt, call the ambos. In QLD, police are definately not in the business of chasing ambulances. The only reason police will be called is if the ambos (or the phone operator) suspect there is a risk of violence, or the situation is unsafe. Thats why its important to remain calm on the phone and when dealing with health professionals. In QLD, it costs around $80 for an ambulance to be called, and $250 for non-emergency transport to hospital (emergency transporting is heaps more expensive). If you choose not to pay the bill, I believe they take no further action. I always think its better left to the pro's.