Hah, now that's a bummer!^
I don't think I have ever dropped a bag of fish, but just the other day I was acclimating a betta in its cup & it jumped into the sink while I was emptying a little bit of water from the cup.
A couple of years ago I had a swordtail tank in my bedroom. One night, a few minutes after I turned the lights off to go to sleep, I thought I heard an odd noise near the tank. I turned on the light again to go check, and my 2.5" female swordtail had jumped from the tank. I was surprised I heard that with an Aquaclear power filter running, since a fish that small jumping out of the tank is barely audible. Who knows, maybe it was more of an intuition thing....