Good question! I have an Induro AKB2 tripod. It seems to hold the camera fairly well if the camera is horizontal. The incident happened when the camera was vertical. I was using the D7000 and an Nikkor 18-300mm zoom. The tripod is rated for 18 pounds so the load should not be an issue.
I pressed the shutter release and the camera fell 6 feet to the ground. I don't think I touched the quick release but I guess it is possible. I don't trust it anymore. Is there a better quick release that I can somehow use with the same tripod/head or should I get a different ball head and or just a different tripod?
The damage was: Battery cover fell off but I was able to reattach. UV filter on lens broke. Ring on camera that lens attaches to needs to be replaced-it was warped.. Lens barrel needs to be replaced (symptom was rough zooming).
Total repair cost is $200 for camera and $400 for lens.
I was at a group photoshoot that night > I couldn't get the broken filter off-the threads on the filter were damaged-- but I was able to remove the broken glass. After that, amazingly enough, the camera and lens worked perfectly despite the damage and I was able to do the shoot and got some nice shots.