@stewmills, Holy mother of f.uck, someone's looking after you. I bought a circular saw recently and whenever I use it, I have all these images of body parts being chopped off.
Sometimes we are so careful but then drop our guard for a moment and wham. The gf was cleaning the chain on her bike and instead of leaving it in gear and turning the back wheel as I told her to do, she instead put it in neutral and spun the chain while holding a rag. She thought this was the fun way to spin the chain till it pulled her finger in. Thankfully she was as lucky as you and did not lose her flute playing finger.
Having had a few close shaves myself, like being t-boned by a nurse coming out of a hospital driveway and ramming the carburettor into my leg, smashing my tib/fib, the accident inspector told me that had it not been a boxer bmw, this would have been a 100% lose your leg accident, I will repeat you were extremely lucky.
If you want to see fearless stupidity check out
https://www.youtube.com/user/colinfurze/videos