I see a literal interpretation has been taken.
I would assume this is your source,
The soundness of the hadeeth “Do not write anything from me…” and explanation of what it means - Islam Question & Answer
We need the full Hadith;
"Praise be to Allaah.
It was narrated from Abu Sa’eed al-Khudri that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Do not write anything from me; whoever has written anything from me other than the Qur’aan, let him erase it and narrate from me, for there is nothing wrong with that.” (Narrated by Muslim, al-Zuhd wa’l-Raqaa’iq, 5326)
One would have to quote the Quran verses that support this Hadith, otherwise it is accused exactly as it is accusing.
But I see a wisdom in it that is also in the Bible and thus we can show why your argument is not valid.
Deuteronomy 4:2"You shall not add to the word which I am commanding you, nor take away from it, that you may keep the commandments of the Lord your God which I command you."
The Bible has a few other verses that say much the same.
Thus I see the Hadith is saying the same thing. It is saying not to add meaning to the book that is not there. The Hadith supports discussing the Word of God.
A good example in Biblical terms is discussing the writings about the Station of Christ and God, but not making a doctrine called the Trinity. A doctrine that was made to stop any other ideas. Thus to me the Haddith says erase the Trinity, just as Muhammad did in the Quran.
The Kitab-i-iqan was written by a Messenger from God. Thus as I said, it is your choice.
To me there is no doubt about that Book, it is the word of Allah.
Regards Tony