Actually, you don't get to see any of the quarantined people die - unless you kill them yourself. You can still imagine that the one without the healing potion is cured later on, since the cure is known.
And while I agree that not all possible solutions should be obvious, stealing one of the healing potions back is a bad example, in my eyes. It's an oversight, if not a bug, that those potions remain in the inventory - as the ill people need to drink (or apply) the potion in order to be cured, the vials should at least be empty. For my taste, it feels too much like cheating to steal a potion back. In designing alternate ways to solve a dilemma, please take care to still make them logical, even if they are odd in one way or another.
I also agree that decisions early in the game should tend to have minor and/or short-term consequences - you probably aren't mighty and famous enough to have a major and/or long-term impact on the world - but that doesn't need to be a rule without exceptions. If, for example, you have the option to save or condemn a character who can possibly play a key role later on, the consequences might even be more drastic the sooner you make that choice.
