[avalaunch]

If it is a statistically rare event then offering a full refund shouldn't be much of a hit to you. If that's not the case then you should let renters know up front that there is a statistically significant chance that despite reserving a room, they may not actually get a room.

[brianchesky]

In this case the guest was, and always would be, offered a full refund when a host cancels. Unless you are referring to something else...?