Stored Leatherman Lens Fogged

Hi Guys, I've got one for you. I've had this Leatherman in storage for about 3 years now. It's in a zippered bag with 3 other flashlights.
I went to get one of the other lights today and found that the S3 lens was fogged up. Those of you who know the S3 it is not easily opened so i cannot explain the fogged up lens. It is not just water moisture because I had it on for about 5 mins til hot, but it was still fogged up. There was not battery in it so it was not leakage. And this was the only flashlight in the bag that was fogged up.

Any ideas, without opening it up?

Thanks Guys.