פירוש על קידושין 59:12

Interestingly, the students of R. Joseph wants to answer his question by really checking things out, to see where the middle of the Torah is. They act like empirical scientists not simply trusting tradition. He even cites another case where they actually counted the letters of the Torah (we do not know the context of this case).
But alas, R. Joseph seems to acknowledge that we do not know if our Torahs are written according to this count of letters. In Hebrew the vowels for “oo” and “oh” can either be written with the letter vav (full spelling) or without (defective). There are other words that can be written in either defective or full spellings. So we do not really know where the middle of the Torah is in terms of letters.