Reply To: R Yohanan motivation

Interesting that Avot D’Rabbi Nosson 4:5 has a different order of events:
V knew that Rabban Yohanan was in the peace camp before the meeting based on his spies reports of R Yohanan arguing with rebels. So, V is ready to listen from the beginning. Then, R Yohanan asked for Yavneh (no mention of other items); and after V agreed, R Yohanan foretold that he will be melech. And the news came – not immediately, but in 3 days. But then it seems to imply that V (not Titus) destoyed Yerushalaim by recounting events forward.

This order of events discards my question about risk, as R Yohanan mentions malchus after the negotiations, and V does not object at all, just takes it is a brocha from a tzadik.