I read that as well and it seemed to me like Mr. Rodriguez wanted to say NO, ABSOLUTELY NOT POSSIBLE but something else, possibly not in Sacred Scripture forced him to say YES, Jesus had a possibility of failing / falling into sin.
Jesus clearly identified Isaiah 35,4 as being about Him (Matthew 11, 1-6)
In Mark 13, 31 Jesus says that heaven and earth will pass away but His words never will. I take that to mean that when Jesus said thing like He does in Matthew 7, 22 / Matthew 19, 28 / Matthew 23, 39 / Mark 14, 49 / Luke 24, 25-27 and over 100 additional Scriptures that speak to the same effect. If Mr. Rodriguez was being serious that he believed the Bible teaches that there existed a hypothetical situation whereas Jesus' words "could have failed" where is he getting this?
At the end of the day if as Seventh-day Adventists and Jehovah's Witnesses believe that Christ had the capacity or capability to sin AND this was a real risk how does this comport with the Trinity Doctrine? Adventist groups believe that if Christ sinned and was subsequently annihilated (eternally ceasing to exist) the group concept of "God" would be changed would it not? Instead of having the 3 Persons united in mission and character there would be then only 2 left in the SDA case and only 1 in the JW case?