Ok ok, I didn't write this thread so that all of you SUCCESSFUL mounters could rub it in my face how sturdy your QS8's have been sitting on your walls!!!
J/K, it's ok I'm tough skinned, I can take it!
No seriously though I was hoping to perhaps save a few of you who may have thought, as I did, that my QS9's were secure, when indeed they were not. I assure you I am very careful when I do these sorts of things, and I was supremely confident that my QS8's were secure. In fact even when I put the speaker back up on the wall, I was sure that I had seated it properly in the bracket. That's why I was so shocked when I got the flashlight out and checked it that I was wrong, it was not seated properly.
So do yourselves a favor and pull a flashlight out to double check if you haven't done so already. If I can save just one Epson printer from the same demise that mine came to, this thread will be worth the trouble of posting it!