Minor MVA?

A private ambulance was on scene already, they had been transfering a non emergent patient somewhere when they came across a car off the roa, slammed into a tree down in the ditch, a good six foot drop from the pavement. The airbag had been deployed and the white shirted EMT is standing there with a pair of bloodied gloves on when we arrive.
"Okay, so I'm transfering the scene to you." She says, very officially and I try not to laugh, she must be new as this is something left unspoken except for major incidents with multiple jursdictions.
"Whats up?" I ask her as the captain gets the cot and the board. The patient is still in the car, a C Collar in place and the EMT tells me she was complaining of lower neck pain, she's concious and oriented and when I talk to her she appears to have no major issues. She has strong and equal grips, her pupils are equal and reactive, she says the base of her neck hurts a little bit but its nothing major.
When I ask her how she ended up off the road she says that she thinks she fell asleep, a relative of hers is very ill and she was traveling to go and see her, she'd been driving a lot over the past few weeks and it must have caught up with her.
We eventually extricate her, carefully slidding the backboard under her and securing her because of the neck pain. She has a minor laceration to her face which at some point stopped bleeding. When I was if she has any medical history she tells me that she has A fib and that she's on a blood thinner called Comudin. In medic school they always teach us that Comudin makes a trauma patient very dangerous. They can have internal bleeding at the littlest trauma. But she seems fine and requests that we take her to a smaller hospital because its closer to her home and all of her doctors are there. Our assessments reveal nothing freightening so we agree and transport her to H.
On the transport in, she's talkative, answering all of my questions with no problems, her vitals remain rock stable and she shows no neurological signs.
When we drop her off in their trauma room she tanks us for our care and signs our paperwork. We leave and return to quarters.
Within an hour we are back at H, a walk in medical had requested a ride to that hospital. He's not critical so we transport him there with no real issues or treatments. An IV, a cardiac strip and a history, vitals. We place him in one of the rooms and I sit down to write my report.
One of the nurses comes in and says "I hope you don't want your back board back. Its on its way to Maine."
Apparently our first patient was still on the board, an MRI revealed fractures to the C 3 C4 and C5 vertbrae. A bleed had also developed in her brain. When I went in the trauma room to check in, her face was swollen and she had no idea where she was or what was going on.
I felt horrible but none of my assessments or tests had showed any reason not to take her to the hospital she requested. I am still trying to acquire follow up information on her but I am suspecting it will not end well.