I don't have very much to add to DeConick's ideas. For example, I have always marveled at the scholarship that can make very strong disjunctions between Jesus' parable of the tenants and the citation from Psa. 118 that builds upon it precisely because the parallel in the Gospel of Thomas follows this same parable with this same citation from Psa. 118! DeConick recognizes this connection, too, and rightly notes that, if the parable and the Psalm weren't connected in Jesus' telling, this connection happened very early on.
I would, however, like to call special attention to one of DeConick's arguments. Too often we read the gospels as if they were legal documents, carefully parsing each word and making precise distinctions on the basis of what is and what is not explicitly said. But the language of the gospels is not coldly descriptive. Rather, it is richly evocative, metonymic language that summons a whole world of ideas and images. DeConick writes,
We must take caution to keep in mind that the development of christology was not a linear, philosophically reasoned, completely coherent process. The first Christians were not deliberately creating a divine Jesus. The process is extremely complex, it involved intense personal and interpersonal negotiations. It was responsive to certain questions that they were trying to resolve. It is organic and dynamic.
For me this means that when they were wondering about a question, and they had an idea about an answer, the idea didn't come to them as a single notion upon which they built another single notion. Rather they got an idea, and that idea brought with it an entire set of images and traditions and scriptures that were already associated with that idea.
In some ways I think this calls into question the "first death then exegesis" analysis in which DeConick engaged in an earlier post. But nevermind. She's exactly right here. As certain connections were made between the disciples' experiences of Jesus' life and death and life again, those connections burst into the Christian imagination (which was always already a Jewish imagination) already embedded in established patterns of discourse. Jesus' death could be interpreted so compellingly in the light cast by the Hebrew biblical traditions not because Bartholomew said, "Hey, I was just reading Psalm 22 . . .," and then sometime later Judas (not Iscariot) said, "Guys, check out what I was just reading in Isaiah 53 . . ." Rather, the earliest Christians were able to understand and make sense of Jesus' death as part of the pattern of the history of God's people, a pattern in which Psa. 22, Isa. 53, and many other traditions functioned.
Despite the relative failure of the church's proclamation of Jesus among first-century Jews, the fact that they were somewhat successful in convincing not just themselves but also other Jews suggests that this pattern already characterized (some?) Jews' understanding of their scriptural traditions prior to the church's proclamation of the gospel. Justin Martyr, a hundred years after Jesus, will have exactly this problem with a Jew named Trypho: The Jews have forsaken their previous understandings of the Law and the Prophets in order to obscure the messianic potentials on which the Christians were capitalizing in their preaching. And while I wouldn't historicize Justin's polemical maneuvering as if he were merely describing Jewish exegetical practices prior to their efforts to mask the relationship between the Bible and Jesus, I would suggest that Justin and Trypho reveal the discursive aspects of reading Jesus in Hebrew biblical traditions and the effort it would take to make (or not make) intertextual connections.