CHRISTIAN REBUTTAL
A Christian response to all of these points might be that Paul was just a fallible human being who made genuine mistakes in interpreting the Old Testament.
In reality it’s hard to make excuses for him and assume he made honest mistakes because according to the New Testament itselfhe had been a student of the leading authority on Jewish Law in Jerusalem, the famous Rabbi Gamaliel:
“I am a Jew, born in Tarsus in Cilicia, but brought up in this city, educated at the feet of Gamaliel according to the strict manner of the law of our fathers, being zealous for God as all of you are this day” [Acts 22:3]

So, far from being ignorant, Paul was highly trained and sophisticated in his understanding of Jewish theology. Even if we accept the Christian response, for the sake of argument, then an even bigger issue emerges:
I want you to know, brothers and sisters, that the gospel I preached is not of human origin. I did not receive it from any man, nor was I taught it; rather, I received it by revelation from Jesus Christ. [Galatians 1:11-12]

If Paul, as he himself claims, was guided by divine revelation then why was he inspired to make so many mistakes in quoting the Old Testament? Christian readers would do well to ponder this point.