I am sorry, but I have never heard of airbnb suggesting a guest make other bookings. I think you misunderstood something. And even though I would probably give a refund if it was an instant cancellation, I can also undestand why he chose not to... I have heard a lot of stories from other hosts about how airbnb went against their own policies, and the host was at a loss, so I undestand why he would want to keep that one.
You said you are also a host, you should be familiar with policies then...
As for different identities, it is probably a co-host. The guests were probably talking about whoever they had contact with.
Are you sure you are a host?