I've been reading the Wikipedia pages about the Pacific theatre in WW2; in the page describing the battle of the Coral Sea there is the following passage:
[...] the scout [from Shōkaku] confirmed that it had located "one carrier, one cruiser, and three destroyers". Another Shōkaku scout aircraft quickly confirmed the sighting. The Shōkaku aircraft actually sighted and misidentified the oiler Neosho and destroyer Sims.
During a battle, mis-identifying a ship is understandable; at Leyte Gulf even Admiral Kurita thought that the ships attacking him were major fleet units instead of mere destroyers.
The thing I don't understand in this case is, how could the pilots see five ships instead of two? How could two independent reports contain exactly the same mistakes? The pilots weren't even under attack, so they had plenty of time to make sure they were getting their facts straight.
If this question is too broad or vague, I'll accept answers detailing the procedures used by Japanese scouts for spotting, identifying, reporting and confirming other people's reports: for instance, was the information transmitted at once by voice radio, unencrypted, on an open channel?
That would explain how the second scout made the same mistake (he could have said "I confirm that" without even spotting any ship).
This is maybe a minor episode, but it altered history in a significant way, so I'd like to understand better what happened.
EDIT: I dug out some more info (even the footnotes on the Wikipedia articles are engrossing); at least some Japanese search planes in the Coral Sea battle had a pilot, an observer and a radioman.
It seems that the information was transmitted in the clear, in fact during the second day of the battle, American ships knew that they had been sighted when they intercepted messages from a Japanese scout plane.
This might explain the identical mistakes from the two scouts - the radioman and observer on the second plane were probably aware of the message from the first one, and even if rank didn't come into play, suggestion probably did.
Finally, another piece of the puzzle might come from a similar mis-identification made during the same battle by an American pilot, John Nielsen: the book Pearl Harbor to Midway explains that "the SBD's coding system was a board with pegs and holes to allow for rapid transmission of coded ship types. In Nielsen's case, the board was apparently not aligned properly". I don't know if Japanese planes had a similar system, but this might explain at least some of the mis-identification problems that plagued the Pacific theatre.