Yeah I saw that episode of DS and disagreed with their decision as well. You always hear that survival is a "calories game'", and how important it is to conserve calories. Then you see them just dump "food that doesn't run very fast" as Cody would say, into the dirt... Makes no sense to me.
If dehydration is the major concern, then just hold on to the beer until you find a water source. Duhhhhh. Then drink the beer (calories), and use the can to boil the water; and rehydrate.. It's gonna take time to get the water to boil, cool, and drink enough to hydrate. By the time your done with that any "Effects" of the alcohol will be long gone.
Maybe you'll want a nap, by your fire, but rest is a good thing.

Me personally, I'm drinking the beer at some point..