Was Jesus a failed prophet?

Mt 24:34 ("Truly, I say to you, this generation will not pass away until all these things take place") is a familiar crux. Did Jesus mispredict the future?

There are different explanations. And I've discussed this on numerous occasions. But here's another angle. The question at issue is the relationship between his fall of Jerusalem prediction  and his end-of-the world prediction. These are adjacent, but are they coreferetial? Are they synchronized?  

This verse is embedded in the Olivet Discourse. That's an extended block of text (Mt 24-25). But did Jesus deliver that entire address at one sitting, or is this a composite text? 

Matthew and Luke both have a tendency to group related material together. For instance, the Sermon on the Mount is often thought to a composite text, where Matthew combined things Jesus said at different times and places. 

In that's the case in regard to the Olivet Discourse, then we're dealing with two or more separate oracles of salvation and judgment. Each is prophetic, but may well have different referents. When combined, there are no editorial seams, so we're left with one continuous block of text–which fosters the superficial impression of one continuous chain of events. But the continuity is literary rather than chronological. Like other composite speeches in Matthew and Luke, there may be no explicit textual clues to distinguish the underlying sources, which were delivered at different times and places. It's just run-on. Yet the impression of continuity is an editorial artifact. There's the original setting for each speech, but in writing a biography, the narrator must rearrange some material to produce a linear flow. Writing is a different medium from speaking. Writing about history is different from how history is experienced.