Verse 9:30 starts, "Sahih International: The Jews say, "Ezra is the son of Allah ....."
No they don't. I have never heard any Jewish claim of the sort. I fail to see how that is not a blatant untruth.
You make a reasonable point here.
However, the manner in which the currrent understanding of the vast majority of Muslims was arrived at is moot (in terms of the situation on the ground - not academically).
There are 2 options:
1. The author of the Quran, a person who was well versed in the religious and sectarian affairs of Late Antique Arabia and the broader region, thought that Jews in general considered Ezra to be the son of god.
2. The passage means something else (for example, it refers to a certain sect of Jews, it refers to someone/thing other than Ezra such as Metatron, it is a non-literal rhetorical device warning against excessive veneration or a polemical attempt to draw parallels between Jews and Christian’s etc).
Given 1 seems very unlikely indeed, painting it as an “error” seems incorrect.
It’s easy enough for Muslims to se it as a statement that refers to specific Jews in Arabia to make it theologically unproblematic, we can’t even say they would be wrong to do this as it is possible. It’s also theologically unproblematic to see it as a rhetorical flourish against excessive veneration of humans or a theological point that giving angels certain powers violates the unity of God.
Whatever way you slice it, other than a naive error, it is easy to explain for a believing Muslim.
From a scholarly perspective, maybe 100 years ago some Western scholars thought it was a naive mistake, that perspective is largely considered untenable these days though.