So far:
Hospital says that Cigna said "use company X for ambulance because it's in-network, so no authorization is needed." But no actual record of this.
Ambulance co says Cigna rejected claim because they don't cover transport at all. Cigna told me that at first, but then said it wasn't covered because there was no auth. Ambulance co is checking to see if auth is needed with cigna.
I have a call into the case worker at cigna who was in charge of this to see what the actual reason for the rejection is and to see what she says about needing an auth. But I've dealt with her before and she's a total idiot. (She's the one who tried to tell me they don't cover any RTCs at all in my state, which isn't true.) So we'll see.
Bottom line is that there is no way I could have gotten authorization--I wasn't involved. A bed opened up at hospital 2 and hospital 1 arranged for transport. Even if I had said "hey wait, let me call cigna and make sure all this is covered" I KNOW the hospital case worker would have said don't worry, we've taken care of all that and it's covered. I know she would have said that. She was constantly telling us don't worry about insurance. We are dealing with that.