Source: Michael E. Stone, "Apocalyptic Literature," Jewish Writings of the Second Temple Period, ed. Michael E. Stone (Philadelphia: Fortress, 1984) 399.
"One might add that an ancient date is implied by the use of 'Son of Man', an old Jewish title, although strangely, for Milik this is a sign of dependance on the New Testament. Moreover, it is difficult to conceive of a late, Christian work largely devoted to the prediction of a super-human Son of Man, existent in the thought of God before creation, which does not make the slightest hint as his (from Enoch's view-point) future incarnation, earthly life and preaching, or crucifixion and their cosmic implications. Further, in chapter 71, admittedly an appendix to The Similitudes, the Son of Man is specifically identified as Enoch. In view of these considerations, then, there seems no reason to exclude The Similitudes from the discussion of Jewish Enoch literature."
Michael Stone is talking about the Similitudes in I Enoch. For him, the existence of a super-human Son of Man in the Similitudes does not indicate that this section of I Enoch is Christian, even though Christians also believed in a messianic "Son of Man."
N.T. Wright makes a similar argument in Jesus and the Victory of God. I don't have the book with me, so I'm commenting on it from memory, and I read Wright's book eight years ago. In my vague recollection, Wright argues that Jesus was crucified in part because he claimed to be a supernatural figure, which struck many Jewish leaders as blasphemy. In Mark 14:62-64, after all, the high priest rends his garments and calls Jesus a blasphemer, just because Jesus told him he'd see the Son of Man coming at the right hand of power. Wright quoted apocalyptic texts in which the "Son of Man" appears to be a semi-divine figure.
Was Jesus nourished at the well of apocalyptic texts, such as I Enoch? We know that Jude 1:14-15 quotes I Enoch as a source. Could such a regard for the book go back to Jesus? Was the Similitude's view on the Son of Man widely accepted within first century Judaism? Not according to Mark, since the high priest considered it to be blasphemy. Maybe some Jews expected the Messiah to be a Davidic figure rather than an enigmatic Son of Man, and Jesus disputed such a notion when he said that the Messiah is David's lord, not his son (Mark 12:35-37). And "Son of Man" was more than Jesus' term for a human being: it referred to a person with divine authority (Mark 2:10, 28).
Was Jesus acting in the flow of a Jewish tradition about a super-human Son of Man? If Jesus was not original in all of his conception of the Messiah, does that mean he was wrong, religiously speaking? Maybe God in his providence arranged for some Jews to anticipate a Messiah who was super-human, even semi-divine.