Regarding hands pointing down: that refers specifically to the fact that on an automatic watch you are never supposed to change the date when the hands are between (roughly) 10 and 2. Really its only for the 10PM - 2AM period where the date change is storing energy or actually occurring, but if you're unsure its always better to change the time. You can damage the gear by forcing a date change when the date change is actually occurring normally. This is true on a lot of different movement types etc. It is VERY possible seeing as by the looks of your post you didn't know this and accordingly you easily may have done exactly what I listed above at some time or another.
http://gearpatrol.com/2013/06/05/com...hanical-watch/ halfway down the page.
http://forums.watchuseek.com/f72/set...ch-447260.html