Wow, I learned something new today. I honestly thought that the extractor slide over the round either way and chambering a round by hand was ok. I will check my rounds and stop doing that. Thanks guys!
As long as you are feeding from the magazine, you are okay.
It is when you are forcing the extractor to have to snap over the rim that you "could' have problems.
You might not ever, but I prefer to be safe rather than sorry. Especially if you are using this method to put in your first defensive round. It would really suck to chip and extractor and not find out until your gun won't extract properly when you need it most.