pub, they mean that since the light or whatever is waterproof, the gas couldn't escape from the battery compartment because it's sealed/waterproof. if water cant get in then gas can't get out. I bet the warning is for liabilty purposes. I doubt it's anything to worry much about....
yes keven, i think you're right, the good ole "cover our ass" clause
btw, how often does your avatar need to take tylenol?
Balincaguin comes from the Zambal phrase, "Bali lan caguing" meaning "house of bats." This was the former name of the Municipality of Mabini, Pangasinan, when it was part of the Province of Zambales (of Mt. Pinatubo Volcano fame).