Two points:
Raen offered Sandrina one of his knives... and she took it, naturely. (You'll find it in her belt, Chrystal.
)
Secondly, Raen noticed a lone horseman leaving the town. He presumed it was a messenger, sending a message back to the estate that Sandrina and the others were en route. If you want me to change/remove that, let me know.
Himaran