Oy vey......Seriously girl, where would they med-evac too?....
I still wouldn't rule out muscles....I have stressed mine at times, it took days for the serious pain to go away, and weeks to feel normal again.
However, you might try to get the coccyx x-rayed specifically.
There is a good medical facillity down in Darwin. I would take a Yajasi flight for that (assuming my med-evac insurance approves) or I could go to Singapore. Again, that is contingent on insurance approval. Either way, since I cannot sit, I'd have to go on a backboard.