I have absolutely no proof of this, but based on my experience, having 3 different Yosemite installs and not reporting the same bugs on all 3, I'm almost thinking that Apple sent me different versions of the same build specific to my problem. I know they say they don't do that, but I can't think of any explanation for me getting different results on what is supposed to be the same build on 3 different installs. Somebody can correct me if I'm wrong, but Apple did respond to me directly about one bug on one Yosemite built. That's what leads me to believe this.