As an anaesthetist who get called to these sorts of things not infrequently, I have a very low threshold for inserting an IO needle in little ones. They are not the easiest things to learn to do, but are certainly life saving. I certainly wouldn't expect the paramedics to try this, although would not criticise them for doing so. I think diesel is definately your best bet, unless you know there will be a significant delay in getting there. From the story, the delay in starting care for this child once in hospital seems worrying - was a senior doc/paed present, or was it just juniors flapping around?