A bit of an update... I have inspected all the cases very carefully that I had fired the day of the "extractor problem". There are no signs of ruptured cases, but one case has a bit of a divot in it near the rim, I'll toss it just to be on the safe side... The strangest thing I found though was a punched in small rectangular mark near the firing pin dimple on one of the cases. I've never seen a mark like this before, and at the time of typing this have no real clue what may have caused it.

I'll try to take a photo of the mark and post it on this thread, but the mark is so small I don't know if it will show up very well in a photo or not. Strange to even stranger... (Shrug)