FYI, I asked David Allen of Photon and here's David's reply:

"Aardvark is correct and has effectively done what we have had to do to fix the issue. The green material we used orginally is a catalyst hardening epoxy that was supposed to be tough and hard at the same time. Most of them are (BUT) when the mix is either old or not right the material is too hard and chips or is too soft and is gooey. I had to take the human element out of the mix as the worker did not always mix and use the material in the manner required. This was changed a couple years ago to a strap that does not need the "extra material". He has the right idea of a fix as if the material is compromised it will short out the top battery. We even tried a clip on insulator before I gave it up and modified the molds to accomodate a new strap design. All of that took about 6 months of testing and work. You will experience an easier battery change with the new design.

We try to fix any issue that comes up as soon as it is identified. And Aardvark has the right idea that will enable the light to keep giving for many years to come."

If you have an older Photon that exhibits this issue you can follow his example and fix it yourself, or send it in and Photon will cover it under warranty.