Why was targum shivim/septuagint such a big problem? This wasn’t the first time the Torah was translated. Wasn’t the Torah already translated into 70 languages at the end of Sefer Devorim?
Great kasha, one answer I heard was that when Moshe wrote the sifrei torah at the end of devorim he was able to write it completely on our terms, whereas when we had to write it by the septuagint it on their terms and caused us to have to censor parts of the torah.
I checked further. maseches sofrim 1:7 says they translated for talmai 2 times. The first time it could not be translsated fully correctly. The second time (brought in the gemara megilla 9) they even made 13 major changes. However when it was originally translated in the days of Moshe and Yehoshua it was translated correctly and fully. (interesting that the 13 changes might correspond to the 13 breaches the yevanim made in the bais hamikdash. v’ayain.)
I saw an esoteric explanation (which was actually quite fascinating), based on the works of a recognized godol b’Torah, from Likkutei Sichot, vol. XXIV, pp. 1-11.