It wasn't just laypeople, it's trivial to go back and find prominent public health officials promising that vaccinated people will not transmit the disease, the vaccines will be 100% effective against death, etc. They shouldn't have been saying that given that what you say about the trials is true, but hey, they haven't paid any price for getting it wrong since this whole thing began so why would they now?
In general I have noticed there's this pattern where the public will sometimes be clearly and strongly led to believe a certain thing, but if it later turns out to be false, 100% of the blame is placed on the masses. If there's any rebuke for the officials or institutions which led them into error it's always in the most vague and general terms, with no one ever indicted (or, heaven forbid, punished) by name.