When Lilah got her hands on the Scrolls, her flunky translator says something about the father will consume the son, Wes translated the father will kill the son. Vampires consume to kill. Technically Angel did consume Connor when he consumed Connor's blood. I mean, blood rained down on the sky when Angel's blood fell on Connor's sky themed blanket. Wes was so sleep deprived and freaked out and hopped up on Angel hurting Connor and Connor being some sort of weird miracle/anti miracle birth he was missing things.
I also think Wesley was still hurting about Gunn and Fred, and Cordy leading him wrong there. His pride was hurt. Lorne's always been the cryptic wild card.
And when Wesley made that choice to go to Holtz, to tell him things, when he made the choice to take Connor, he betrayed his friendships. Not just with Angel, but with everyone else. He was willing to trust and believe Justine over any of his friends. And look where that got him.
Wesley isn't very self confident, but he can be arrogant. And that's what gets him into trouble. He's in this constant conflict with his arrogance and uncertainty.
But, back to Wesley as Betrayer.
Wes did betray his friends. He betrayed everyone that put his trust in him. Angel trusted Wes to keep Connor safe and protected from Holtz and Wes betrayed that. Wesley didn't sell everyone out for money, but he sold them out for his arrogance, he thought he could play both sides and manage to keep Connor safe. So he betrayed Angel and Connor to Holtz, and Holtz betrayed Wesley.
So, I think in that way it's just a common shorthand to relate Wes as Judas. Plus Lilah gave Wes a copy of Dante's Inferno, and in Dante's version of Hell, the center of hell, Judas--the Ulitmate sinner, the Ulitmate betrayer--is forever alone. And here we have Wes. Cold and alone. With no one. Except Lilah to come around occasionally and twist at his wounds a bit.