1. if I have a uniform/undefined prior (how the fuck should I know how risky/conservative firefighters are?)
2. and then I'm given an anchor
3. and then told the anchor is bunk
4. the anchor still affects me
But I suspect this hinges very heavily on the fact that our initial prior is basically non-existent. By contrast, if you:
1. picked a topic where I actually have some prior belief (What country is colder: Sweden or Germany?)
2. gave me some information "Germany is actually colder on average than Sweden because of a weird atmospheric thing that affects the nordics"
3. told me that 2 was BS
I highly doubt you'd be able to replicate 4.