How would the sailors on the ship being attacked be able to know anything like that (e.g. know if the Israeli pilots thought they were attacking an Egyptian ship or an American one)?
The sailors would know because they have access to the same information that you do, but a greater incentive to actually do the reading. The Israeli pilots knew it as a US ship, their radio traffic questioning their attack orders - after visually identifying the USS Liberty as a US ship, was recorded and the transcripts widely known about. This happened several times, so unless the Israeli command center had the memory of a goldfish - they intentionally kept sending attack aircraft until they eventually got a pilot to pull the trigger. Why would they do such a thing? Because the US wasn't onboard with the Israeli preemptive strike and they didn't want a signals intelligence boat tipping off the Egyptians. Israel doesn't appear to reciprocate the fond feelings expressed by American politicians - the mere idea of the "Samson Option" is proof enough of that.
To that point, it's worth noting here friendly fire incidents happen all the time in war, as well as attacks against neutral parties. For instance: the US has bombed its own troops probably more times than anyone can count, and it also bombed the Chinese embassy in Belgrade and shot down an Iranian airliner. Why would they do such things? Honestly, it's plausible they they may actually have had the memory of a goldfish, at least occasionally.
Because an imputed motive is not proof of anything, and there's no way "accounts on the ship" could provide the information you claim they do (knowledge of the attackers mental state).
I don't think anyone disputes that the Israelis attacked the ship intentionally, but you can say the same about most friendly fire incidents. The question is if the people who made the attack deliberately decided to attack what they know to be an American ship.
Given the general incompetence of governments in general (Europe is no exception) I doubt it is (b).
Reminder that France vacuumed up messages on Enrochat after deploying malware globally, and they have clear text messages from users in any arbitrary country and have not disclosed what they will do with it or what they have.
https://www.vice.com/en/article/3aza95/how-police-took-over-...
The US spies on everyone because they can, and because they have prepared to do basically anything they think might be in their interests; when Germany discovers the US spying on them, what can they really do about it? Whereas if it was the other way, all hell would break loose.
Establishing mere capability is pretty trivial: they have diplomats in the United States who can talk to people.
You don’t think the French would love to have known about AUKUS submarine deal before it was made? It’s detrimental to not attempt to spy. The French were blindsided and I’m sure they don’t want to be blindsided again.
[1] https://www.space.com/arianespace-soyuz-rocket-launches-cso-...
As for the USS Liberty, some do argue that it was intentional, but both the Israelis and Americans ended up agreeing that it was a mistake. The US is no stranger to such mistakes either, even more egregious ones like when they killed close to 300 civilians aboard a regular passenger flight following an approved route and in contact with ATC (Iran Air 655).
In the end both the US and Israel are amoral states that act only according to their economic and strategic interests and I feel that this unites them. I wish it didn't, though.