In the case of Bertie's example (even if it's only half true), the management team of the charity are at fault - and their trustees for not providing sufficient oversight. There should be a sufficiently robust SLA between the charity and the local Ambulance Service which prevents an air ambulance asset being used merely to cover the lack of road assets. Every charity I know, works on these.
But if it's TAAS, they are undoubtedly focussing on other things that are important to them, like taking over the world.
Getting tasking right is never going to be an exact science. But if all parties agree on the correct measures and work towards them, it's a Good Thing.