Interesting. I get the following message when I run that:

Msg 3101, Level 16, State 1, Line 2

Exclusive access could not be obtained because the database is in use.

Msg 3013, Level 16, State 1, Line 2

RESTORE DATABASE is terminating abnormally.

At least it seems like an acknowledgement that the database exists. I can't see any connections to it using sp_who(2), it doesn't show up in SSMS, and it doesn't show up in select * from sys.databases.

Very odd.