Oh no, it's better than that. The US commander in that battle also believed that the enemy fleet was friendly. The difference is that the Japanese fleet obeyed their confused commander's orders. The American fleet reinterpreted their commander's orders.
Basically, the US commander said "Roger" and meant "Roger, I heard your report". The US ships heard "Roger" and interpreted as "Roger, attack those Japanese warships".
Oh, well, while this is back up in the comments section...
Karma was pretty swift on this one. Aoba didn't get away scott free, herself. The kuso TTK that was responsible for sinking his subordinates was killed when Aoba was struck in the bridge.
Also, Furutaka didn't draw fire because of flashing her signal to save Aoba. Aoba actually put up smoke while trying to turn around to lose the ships shelling her, and the Americans misinterpreted that as Aoba already sinking, so they changed fire to a different target. (Which is if anything, is slightly less heroic for Furutaka, and more dickish for Aoba.)
Kinugasa and Hatsuyuki survived because they chose to circle around by turning to port, rather than starboard, and therefore, didn't turn towards the Americans while not firing back.
Basically, the US commander said "Roger" and meant "Roger, I heard your report". The US ships heard "Roger" and interpreted as "Roger, attack those Japanese warships".
In those ships' defense, this was because some genius had designated "roger" as the specific code word for "open fire" in the most recent rev of the radio code. Moral: don't pick words that already have a universally accepted meaning in radio traffic as code words for something else. There are two different ways it can go wrong!
In those ships' defense, this was because some genius had designated "roger" as the specific code word for "open fire" in the most recent rev of the radio code. Moral: don't pick words that already have a universally accepted meaning in radio traffic as code words for something else. There are two different ways it can go wrong!
Yeah, for example if it had turned out it really was another American fleet he'd have accidentally told his ships to fire on them.
I've detected a friendly transport convoy.Eh!?
Would a transport convoy really come here?FurutakaNo, those silhouettes in front are enemy ships.FubukiNo, I'm pretty sure they're enemies though!?I knew they were enemies!!Ehhhhh...Flagship AobaEh!?They're firing on us!!Furutaka sunk.Ah, they're enemies!!I will use my light to distract them!!
I am Aoba!KinugasaCape Esperance*flash*You’ll get fired on if you stand out so much like that!Please watch this!!
THIS IS AOBA!
THIS IS AOBA!*flash*Hatsuyuki*flash*Aoba retreating!!I freaking told you!!GyaaaaaNow, let's confirm it!Counter attack.GyaaaaaaaaaaaNow escape, quickly!!Furutaka, what are you talking about!? Those are friendly ships! Look clo-…What!? She still thinks those are friendly ships!? Rear Admiral Gotou thought the (American fleet) ships they sighted were friendly ships from Rear Admiral Joujima's supply convoy and flashed the Aoba's identification signal. She got bombarded because of it.This is friendly fire because we can't see each other in the dark!No, (I can't see them well, but probably) they're friendly.If you're that suspicious, then we'll just have Fubuki-chan go and take a closer look!!That overly friendly enemy ship keeps coming closer…. What are they!? Too scary!! Don't come any closer!Fubuki-chan!!!!FubukiSunk
(actual history)It was all Aoba's fault...