This is a take that shows an appreciation for the issue but stops short of getting to the obvious conclusion, that Islam is false either way. I don't think the dilemma was well represented. It goes something like this

- The Quran affirms the inspiration, authority and preservation of the Torah and the Gospel

- The Torah and the Gospel contradict the Quran on several major issues

- If the Quran is right about the Torah and the Gospel being authoritative, Islam is false because it's message does not line up with the Torah and the Gospel.

- if the Quran is wrong then Islam is false because it affirms false scriptures and it's key source, the Quran is a false book.

There are also other things in Islam that lead to this dilemma like the mention of "Christ" or "Gospel" for example.

The debate on corruption is unnecessary because Surah 6:115 says NO ONE can change the words of Allah and Surah 3:3 says Allah revealed the Torah and the Gospel, so to say people corrupted Allah's words in any sense (other than the interpretive sense ) would be an insult to Allah.