O-rings on a Pelican 2680 Light

I just bought one of these from you.
I have two questions about the O-rings.
First - there are two of these on my model (on the lamp assembly).
Does this model ship with a spare O-ring?

When I screw down the lamp cover so that the LED makes electrical contact and shines, the second O-ring bulges out of the side of the screw-down assembly, which I have a hard time believing is right.
If I remove the second O-ring then everything seems to work fine, but I haven't tried it for being waterproof in this condition.

I plan on using it for scuba-diving so waterproof-ness is quite important

How many O-rings am I supposed to use?

I spoke to Pelican. Your light uses two O-rings. One goes "below the ridges
all the way to the bottom", and one "sits on top where the lens tightens all
the way".

They were very helpful and said that you may contact them directly at
800-473-5422, and if you need extra O-rings they can ship some out to you.