Think about what you're saying. If it were written by one guy, then it would be easy to make things up and make it fit together, if it were written by 40 people and most of them didn't know each other and lived in different parts of the world, that would be impossible to make up and have it fit together perfectly as it does. The fact is that God told them what to write and they wrote it down.
i dont think Muslims dispute the idea that Bible is God's word. However, the inaccuracies in it are a result of the numerous scribes inserting their own words, knowingly and unknowingly, into the scripture.
Merely the fact that many people are responsible for transmission and publication is not proof of divine status in its entirety. For example, Homer's poems were not written down for centuries, and many passages have doubt about who wrote what, whether or not they are indeed Homer's words. I think this is the nature of doubt Muslism have about the Bible.