That's sounds like it hurt! High velocity books are not fun (I know from the idiot jocks who used to whip books at people in library whenever the teacher left the room). Just jumping wrenched me up pretty good.
Rather strange sensation when inanimate objects decide to go all "CHECK ME OUT!!! I'M NOT SO INANIMATE NOW AM I, BIZNOTCHES??!!!"
Because I had the cans on with a track running it was all completely silent too (to me at least). My neighbors must think I had some kind of meltdown because there may have been some startled utterances. lulz
There was also a bit of an after shock as I was trying to clean up the mess. The top shelf gave way too after a couple minutes. Fortunately I had already put my hard case (that I use for mics) against the inside of the unit so the one side of the shelf collapsed but landed on top of the case. That shelf is where I keep the more loose stuff and spindles of discs. Those totally would have went flying everywhere otherwise. Ooof.
Edit: HAHAHAHA!!! I just went to listen back to what I had been working on but forgot about the interrupted guitar take. It was DI so no yelling but you can hear the urgent freakout as I stop playing then some frantic whacks agains the guit. Reminds me of live recordings where a fight breaks out or someone gets beaned with a bottle. I seemed to have the wherewithal to stop transport though.