This is what happens when you attempt to sit down on a shop stool that isn't actually there, and end up sitting on a random power tool (thankfully not running at the time) instead.
And in detail:
So what happened, I backed up, bumped the stool over without realizing it, then a minute or two later, I went to sit back down on the rather high shop stool, and ended up falling back over onto the aluminum fence of my portable sliding compound miter saw.
Not fun at all.
And that little present is after just a couple hours after. The real fun is the next day... or two days later, when it turns green.