It's not unusual for an extractor rod to back out. In revolvers with a front locking bolt, you would know about it before it had a chance to completely loosen because the gun would open or close hard. The R8 doesn't have one of those so the rod was able to back all of the way out without binding the cylinder when you opened it. I would keep away from the lock tite. I have made checking the tightness of the ejector rod part of my cleaning routine. A good addition to your tool kit is one of the ejector rod tightening tools from Brownell's. Remember to put empties in the cylinder to back up the ejector star when tightening or loosening the rod. And remember that it is threaded backwards. Lefty tighty, righty loosey.
Under normal circumstances and every one else's experience with shooting revolvers, the extractor rod 'could' have backed out. That would be an extremely normal possibility.
I do have an extractor rod vise grip tool (ordered from brownells) that I did have to use on my 986. I'm well familiar with removing and installing the extractor rod.
And as you do mention, there is no front locking blot(correct nomenclature escapes me at the moment) on the R8's that differ from other models, instead its cylinder relying on the center pin and ball detent for closure, would I have figured out a backing out rod.
Instead , the few threads of the rod snapped off in the extractor itself, and at that moment, when opening the cylinder, caused the rod to fly out with the little tension the center spring still had at the moment of opening.
After the revolver was inspected at the factory, they concluded a "broken extractor " on the work order , fixed it and it arrived yesterday.
But this is what I'm saying or meaning:
That cylinder was replaced at 1600 rounds. It now has about 3k rounds.
It took 1400 rounds on the threads (that were over tightened at the factory at 1600 rounds) to snap off and fling itself forward!!![emoji33][emoji33][emoji33]
Like, that's crazy right! They over tightened it, and it came to break off a few months later after 1400 rounds of use. [emoji2962]