Everyone else has already said it. Good recovery. In most cases, the "act like nothing's out of the ordinary and no one will have reason to think otherwise" usually works. You've scooped it up and concealed it so quick and acted like nothing happened, that even if someone did see it, they might not be entirely sure of what they saw. No harm other than some scratches. Scratches are unfortunate, but they become battle scars. They add character. They tell a story, your story being better than most. Someday the conversation will be, "No, really, I dropped it right there at the State Fair! That's where it got this scratch right here."
On a side note, it makes you think about retention. A bucket attached to your hip, into which you dump your gun, might be secure enough for standing around. At the opposite end of the spectrum, if you're doing gymnastics, you'd obviously need something a bit more secure. You say this holster holds the gun fairly tight, "retention strap that requires a large amount of force to open." I'd probably get home and experiment (with a triple-checked empty gun) with bumping it from different directions to see if I could recreate the situation (over carpet or something so I wouldn't cause further damage). Maybe it's just one of those freak things that couldn't happen again in a hundred years. But you should evaluate that and make sure.