Sorry to hijack your question to Doug, never had a 'traditional' kickback but I've got an 'interesting' story.
When I was apprenticing about 25 years ago, the firm had a big dimensioning panel saw. The type where you could cut 10'x4' sheets on your own, the only help you needed was to lift them. When I started there, the guard and riving knife had been removed (for grooving) and never replaced. I cut a piece of 3/4" blockboard with an offcut roughly 14"x14". As I went to get the piece I needed, I accidentally nudged the offcut into the rising teeth and it was launched at an alarming pace. It had a decent amount of weight and didn't stop travelling until it hit a set of office drawers about 12 foot away and 4 foot off the floor
The thought of getting that in the face is still frightening. The foreman (the genius who removed all the safety features) usually spent large amounts of time standing next to the drawers (his desk was right next to them). Fortunately, he was brewing up at the time so I got a cup of tea and a lot of verbal abuse