It is the same man who told her to go to the police, as far as Sarah can tell. Also the same man Svetlana talked to at the river, if she bothers to look.

The man turns his head slowly to look at Koutarou, but otherwise stays put. "... you're welcome", he notes, barely audible through the rain.

As far as the answer to Sarah's question goes, nothing seems to be going on. Just the four of them in the rain.