This just seems like a not great example to make that point though. Since whatever Claude tells the kid looking to build a reactor or even bomb is almost certainly going to be more grounded and professional than:

  Step 1. Obtain pliers 
  Step 2. Obtain 300 discarded smoke detectors 
  Step 3. Start yanking!

Instead it would send them on a wild goose chase for unobtainable isotopes, centrifuges, heavy water, etc where the biggest risk is probably getting reported to the police by some chemical or industrial equipment supplier. Which is a better outcome compared to contaminating their home with radiation and exposing anyone they interact with.

You'd maybe get a sketchy but near-viable plan that could be dangerous if asked for a dirty bomb, but there the danger would more be the conventional explosives and not where to source radioisotopes, as it was already common knowledge that most residential smoke detectors contained americium until recently.