Does the Koran contradict the Bible?

I'm going to discuss related statements I saw on the Internet by two Christian philosophers. The first said:

Just ran into someone claiming that the God Muslims follow is not the same God as the true God of Christianity, immediately followed by the claim that Muslims are blaspheming God. Take your pick, but I'm not letting you have both of those claims. If they're blaspheming God, then it's God that they're blaspheming and not some other god.

But that's a false dichotomy. Suppose, as a prank, a college student puts the dust-jacket of a Bible on Aleister Crowley's Diary of a Drug Fiend. His roommate, a recent apostate and rabid atheist, flies into a rage when he sees the book, which he takes to be a Bible, and burns it. 

Did his roommate commit blasphemy? Objectively speaking, no. In fact, the book that he unwittingly burnt was a blasphemous book!

Yet he intended to commit blasphemy. He meant to destroy a Bible as an act of sacrilege. So his action was subjectively blasphemous.

The second said:

Now suppose you think, as is plausible, that when the Quran says that God has no son (Q4:171; Q6:101) it’s contradicting the Bible (John 3:16, etc.). In that case, you’re presupposing that the Quran is referring to the same God as the Bible. Conversely, if you think the Quran is referring to a fictional, non-existent deity when it says that God has no son, you need to consider whether the Quran is actually contradicting the Bible in saying so (and if it is contradicting the Bible, how it is doing so). The same goes for other objectionable statements the Quran makes about God. 

If you say the Quran is in fact referring to the God of the Bible (because it make false claims about the God of the Bible) are you thereby implying that Christians and Muslims “worship the same God”? Not necessarily. It all depends what you mean by “worship the same God”. 

http://www.proginosko.com/2015/12/on-contradicting-the-bible/

That raises several issues:

i) Some commentators think these statements reflect Muhammad's garbled, hearsay grasp of the Bible or Christian theology. He had no direct knowledge of the Bible. If so, he's not actually attacking orthodox Christian doctrine. Rather, this represents his misunderstanding of Christian doctrine. 

On that interpretation, Muhammad meant to attack Christian theology, but it was a failed referent. Burning a straw man.

ii) Other commentators think Muhammad is attacking the theology of certain heretical sects. If so, this could be based on firsthand information. It might be reflect an accurate understanding of what they taught. It is not, however, an accurate description of orthodox Christian doctrine. If it was intended to attack Christian theology in general, then it's a failed referent. 

iii) Still other commentators think Muhammad was, in fact, attacking orthodox Christian theology. If so, in that respect it's is about the same God or same Jesus as the Bible. That, however, is contrary what people mean who say Muslims and Christians worship the same God or believe in the same God. For in this case, Muhammad is contrasting Allah with the Christian deity. Muhammad is saying Allah is the one true God in opposition to the Christian deity. 

In that case, it might be possible to affirm a common referent, but deny common belief or common worship.

iv) As to whether the Koran contradicts Biblical theism if Allah is a fictional, nonexistent deity–the worshiper of a nonexistent deity can intend to contrast his god with the Biblical God. Take modern Hindu nationalists who persecute Christians in the name of Lord Rama or some other mythical Hindu god.

v) Finally, we could turn this around. The Bible mocks the idol-gods of paganism as "vanities". There's a sense in which the referent concerns heathen beliefs rather than gods. What they think about gods.  

(For convenience, I've framed the discussion in terms of what Muhammad thought and said. But due to the murky editorial history of the Koran, we don't know how much of the Koran actually goes back to Muhammad.)