Yeah, these close calls are a regular occurrence. One time I was wing walking when a friend pushed a Bro and I went around to the right side to grab the gear pin as the pushed stopped. As I grabbed it, I noticed the prop on the other side ever so slowly starting to turn...with a coworker still struggling to get the pin out. There was a few seconds of "Wait...." then I turned around and shouted at the marshaller but luckily he had just noticed himself as I saw him pointing at the #1 engine and desperately doing the "cut off" signal. When we talked about it, it turned out the CA didn't wait to be shown the gear pins and asked to start number 1. The marshaller had a brain fart and approved it. So now the prop is spinning with a ramper having his back turned to it, which resulted in him turning around and walking between the prop blades AS they were (slowly) moving and he didn't even realize he was ever in danger until we told him afterwards. The plane itself made a round trip and returned to the gate next door and the CA actually came over with the F/O and apologized to the ramp lead and said he'd take responsibility if we reported it, but we didn't. I'm sure everyone involved would never make that mistake again.
But even with a system of checks and balances to prevent it, these things happen. Thus, while some people look at walking into a prop as being as stupid as getting hit by a horn blaring train, I do have sympathy.
