Cool. You found it. Glad nothing else was hurt. I guess that specific bushing never made much of an impression on me working on the rear suspension. Mine is not an ABS bike so it is pretty easy to slip that bolt out and in so the bushing being there was pretty transparent. I honestly do not even remember taking it out ever despite having the shock out several times. The clue, once you pointed it out with the circle, was how far the bolt was sticking out of the nut. Lots less excess threads showing now I bet with the bushing in place.
When mine is on the center stand there is about an 1/8 of an inch or less of play in then rear suspension measured at the tire. It isn't real obvious as you have to pry with a fairly good sized pry bar to get enough leverage to easily pick the tire/wheel/swingarm up to feel the play from hanging to where the suspension picks up. It isn't much but there is a tiny bit there. Hard to say, specifically. Just a lot of joints in the rear suspension. If each has just a tiny bit of clearance magnified by the length of the swingarm you will sense a little free play at the tire. Since the tire/suspension is always in compression it really doesn't matter for what a street bike has to do.
