xkcd

You fail the saving throw. The curse takes hold of you, the Bane of Thorny Improbability, which damns its bearer to be eternally plagued by probability and combinatorics conundra in their adventures.

You know that you possess an antidote to stave off the worst effects of the curse, but you have three unlabeled flasks at your belt, all of which have an equal probability of being the cure. You choose a flask at random, but as you seek to dislodge it, one of the other flasks falls to the earth and shatters. The liquid eats through the rock of the cavern, giving off acrid smoke, and you recognize that the fallen vial was a deadly poison, not the cure.

Knowing that the second flask did not contain the cure, do you have a better chance of salvation by drinking the flask you originally chose, or switching to the remaining unfallen flask?