For clarity's sake I turned the lights on and then submerged them in a 12 oz cup of tap water. Once they were in there I didn't touch them other than to check for any leaks and to make sure temps were fine.
I think this is THE key piece of information buried within the clutter.
All of this IPX rating discussion is very interesting and educational but was initiated out of speculation. In context, it's a sidetrack given the OP's particular experience. He didn't operate the light, other than to have it activated before it went into the water. Likewise, the water ingress issue is well associated to Zebralight, with several examples having only been rained on.
Pressed bezels are inherently and historically inconsistent concerning water resistance, the Nitecore Explorer series being another recent example. In light of all of this, I think it's very assumptive for anyone to suggest that significant numbers of Zebralight have been gratuitously replaced under warranty. The later IP ratings are fairly ambiguous leaving a certain responsibility of description to the maker. If the manufacturer
gives the impression that a light is safe within a specified depth but then doesn't describe the type of use or non-use within that depth and the light then leaks, guess who's going to eat the replacement. It's probably safe to assume that the manufacturers anticipate the user's expectations (based on their own advertising) and typically exceed the assigned ratings. I've witnessed this is my own water resistance tests, many of which are on video, where I operate the UI aggressively underwater. Keeping in mind that the IP ratings are typically exceeded by manufacturers, actual water ingress can probably be chalked up to a construction inconsistency which the manufacturer did not intend.
