A battleship is not an aircraft carrier.
What tipped you off?
I explained this to the staff. If it had been me, I’d have doubled back on the subcontractor and told them to correct, reprint and express ship the corrected poster. This is now. It would all be on a digital file. Pending that, I’d dummy up a corrected caption and paste it over the original. But this is now. A lot of people neither know nor care enough to be embarrassed about such mistakes.