I did wonder why Ben said the day after he found out he had a tumour a spinal surgeon fell out of the sky (or something like that) - obviously Ethan specialised in other areas. Not surprised he was a doctor - he helped recruit Juliette and treated Claire.
No evidence that Ethan specialized in spinal surgery, though. And let's face it, if the day after you find out you need spinal surgery a spinal surgeon crashes on your "invisible" island, you'd probably take it as a sign as well. If I needed brain surgery and a brain surgeon crashed on my invisible island the next day, I would want him to hopefully operate on me, even if Jack were already there. Someone specializing in
exactly the thing I need help for to keep living? Yeah, I'd see that as a direct sign from God lol.
