It is pretty much understood that it was intentional.

No it wasn't. The wikipedia article you linked stated the investigation on both sides concluded it was accidental. The credible sources say it was accidental.

Your own article from haaretz says that there isn't any hard evidence. There is some selectively isolated quotes, but they may or may not be true and we don't have the full context behind it. The article goes into more comments and quotes about if the pilots knew, it would basically amount to negligence. It does not mean the Israel government was behind it.

See quote from the historian in the article: “Attempts to explain why Israel was interested in attacking the Liberty have failed thus far," he continues. "They’re trying to answer the question ‘Why?’ and they’re having difficulty. It began with the claim that the Liberty discovered the Israel Defense Forces' intentions or preparations to occupy the Golan Heights. And then they said it had homed in on some preparations in Dimona [the site of Israel’s nuclear reactor]. And finally, that it had listened in on the slaughter of Egyptian prisoners of war – I don’t know how slaughter sounds on the communications network. All kinds of bizarre theories.

"If we start with the assumption that the attack was deliberate and planned in advance, the question is why. And nobody answers this question. The answer is that it wasn’t planned."