FastAttack,
Well, it sounds like there were no DAAs in that process. I have seen people get the little lanyards for the lense cap and sun sheild caught in their O-Ring and cause flooding. In fact, when I was in Grand Cayman a few weeks ago, someone did it.
I'm not sure how much grease you put on the o-ring, but since this isn't a friction (there's no rubbing on it when the case closes), you can really put just a little tiny bit. I go around the o-ring many times while greasing it. Each time I go around it (lightly pinching it between my fingers to spread the grease), I check for anything with a lighted magnifying glass. I can also feel anything usually.
I have noticed (and you should check yours) that the olympus o-rings can be a bit rough on the seam with excess rubber there. This would definitely be an issue that I would think olympus should pay for.
As long as your chanel was clean before you put it in (use a lint free cloth with a little grease on it to wipe the channel clean) and the o-ring remains clean after it is inserted. You just need to wipe clean (with same lint free cloth) the opposite side of the case and close it up making sure none of the metioned lanyards get caught.
The only other thing that could cause the flood is if the orings on the buttons failed which again should be a deal that olympus pays for since it is brand new.
You mentioned a shore dive... Did you check the camera again when you first got in (I always do even though no bubbles in rinse tank). I am not sure how long it took to flood based on what you said. If you got down to a depth of maybe 30 feet or so, it could have been something that caused the flood that you would have never seen in a rinse tank. If it flooded right away, that is something that should have been more obvious or a failure between the rinse tank and the shore dive.
I'm not sure if all my rambling helped or not (hate to see a flood or even hear of one,
![Frown :( :(](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f641.png)
).