No, he did not twist Scripture. Genesis 6 IS... about fallen angels mating with the daughters of Adam. If you cannot understand why... that happened, it is because you failed to grasp how Satan continually attacked the Seed of The Woman that Jesus was to be born through, his first attempt was the murder of Abel. Even with king Herod, he ordered all firstborn infants to be killed in hopes of including baby Jesus.
Here is further Biblical proof of the existence of the hybrid-giant race...
Isa 26:14
14 They are dead, they shall not live; they are deceased, they shall not rise: therefore hast Thou visited and destroyed them, and made all their memory to perish.
KJV
That is one of two places in the KJV where the translators failed to bring one of the names of the giants, Rephaim, into English.
We know per God's Word that even the wicked dead will have a resurrection, what Lord Jesus called the "resurrection of damnation" in John 5:28-29.
But THESE in Isaiah 26:14 here, it says, "they shall not rise". That means NO resurrection for them. And that is pointing to the hybrid-giant race which was a product of a group of Satan's angels that took wives of the flesh daughters of the man Adam, trying to taint the bloodline of the Seed that Christ would be born through.
This also is why Genesis 6:9 states that Noah was "perfect in his generations", which the Hebrew word for "perfect" is the same word used about the blood purity of sacrificial animals required for OT sacrifice to God. Noah had kept his bloodline from the man Adam pure, and had not mixed with those other peoples. So that definitely reveals the attack of that time was upon the bloodline of the Seed of the Woman that Jesus would be born through. Thus the reason for the flood.
Because Genesis 6:4 says, "and also after that", it means even after... the flood, there was a 2nd irruption of the angels mating with flesh woman. With those offspring of giants, God commanded the children of Israel to literally wipe off the face of the earth. And those giants just so happened to live mostly among the nations of Canaan (like the Emim, Anakim, Rephaim, Zuzim).