They could be the wrong kind of Crane, the one that wanted the war and now is trying to see what has gone wrong.I think the plan was to save up for Intelligence 5? Not completely sure, though.
This might be an opportunity; if he can get confirmation that those people are the Crane, it's possible that we might be able to cooperate and coordinate our efforts for greater efficiency. In addition, this would no doubt earn us some more points with the Crane. And might get us a closer look at how they operate, which might be handy for our Clan in the future.
Of course, that also depends on whether such cooperation between spy-groups is a thing(tm).
This might also be an opportunity, albeit in a somewhat roundabout way.
Miyako just had her participation in the Wager effectively destroyed, even though she was a favorite for outright winning it. The reason were sudden and unexpected gusts of winds, and we had an encounter with a spirit of air not too long ago. We could tell her about it (not the details, of course), and voice the possibility that this spirit, or a similar one, might have been playing a trick on her, along with the suggestion that she seek out some local priest/shugenja in order to learn how to turn the spirit's attention away.
Done correctly, this might earn us her personal gratitude, and thus an in with the Mantis delegation, which could be handy.
On the second, I would like to see what the Mantis lost in the wager... so we have an idea on how much they were hopping for this win