I recently did almost the same thing, except all the weights I used were the wrong ones. It's been about a month, the metallic taste is gone, and it seems OK. I haven't drank more than two of the beers in one night, but I've never felt any ill effects. I still contemplate just dumping it though, you never know the long term effects of something like this. I also don't really offer it to guests since it's questionable, which is another reason I may just dump it.
Since you only used one, I'm guessing the flavor will fade quickly and drinking it all would be fine. But for me, having it in the back of my mind while drinking it is kind ruining the experience..