That still doesn't even come close to proving that homosexuality is a choice.
I am not doubting than some people are predisposed to be attracted to the same sex, much in the same way people are prone to addition of drugs, alcohol etc.
However I do believe people can overcome this desire much like any other desire. As Ephesians 4:27 says don't give the devil a foothold.
Nobody ever became an addict without first making the choice to try the drug. Nobody ever became an adulterer,sexually impure, or homosexual without action.
By action, or giving the devil a foothold, one can be overtaken with one's desires.
Romans 1:26-27 (New International Version)
24Therefore God gave them over in the sinful desires of their hearts to sexual impurity for the degrading of their bodies with one another. 25They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creatorwho is forever praised. Amen.
26Because of this, God gave them over to shameful lusts. Even their women exchanged natural relations for unnatural ones. 27In the same way the men also abandoned natural relations with women and were inflamed with lust for one another. Men committed indecent acts with other men, and received in themselves the due penalty for their perversion.
8Furthermore, since they did not think it worthwhile to retain the knowledge of God, he gave them over to a depraved mind, to do what ought not to be done. 29They have become filled with every kind of wickedness, evil, greed and depravity. They are full of envy, murder, strife, deceit and malice. They are gossips, 30slanderers, God-haters, insolent, arrogant and boastful; they invent ways of doing evil; they disobey their parents;32Although they know God's righteous decree that those who do such things deserve death, they not only continue to do these very things but also approve of those who practice them.