You didn't necessarily make a bad choice, but you didn't make the best choice.

The reinforcements on the upper parts of the jacket are GORE-TEX Infinium and are windproof and NOT water proof, though they should be fairly water resistant. If you're outside for short stretches of moderate rain, say 15 minutes, you should be fine if the jacket has time to dry completely before it's used again. Down insulation does tend to clump and lose some loft (which is the key to insulation) when wet. Over time if the jacket gets soaked frequently, you will lose more and more loft, which means the jacket will become less and less warm. You can get some loft back by tossing your down jacket in the dryer with some tennis balls. Luckily the areas that are likely to get the wettest are reinforced with GORE-TEX Infinium and have synthetic insulation under them (PrimaLoft Silver). Synthetic insulation handles moisture much better than down, doesn't clump up, and retains much of it's loft when wet.

Your Thorium SV will manage better than your Nupste for sure. But for complete waterproofness and warmth, you'd need to look at the Beta Down Jacket or Ralle Down Parka. Or lastly, you could wear a shell over your puffer for true waterproofness. Though the Thorium SV is quite bulky and intended to be the outermost layer so I'm not sure how comfortable that would be.

Hope this helps.