I think the error made here could also be described in Bayesian context: your posterior shifts to the other side because you keep counting repeated instances of the same information as new evidence.
That would be an error if you know the repeated evidence has correlation 1. The studies try to make this clear to the participants, but it's plausible that after a week they forgot where they read some of the repeated facts and treat them instead as independent information. I'd be interested to see how the interval of repetition affects the results.