Agreed, the headline says "AI advice made people three times less accurate". But if we really want to know how accurate these people were, we need to know how accurate the AI system they use is. If the AI system is hobbled to a point where it is worse than they reasonably expect we can't blame the people or the AI system. This would be the same as claiming the listening to experts make people less accurate in a study that told experts to lie.

A better headline would read, "Very inaccurate AI made people less accurate" but this would make people naturally ask, "what about a reasonably accurate AI?".