PHP SDK Delete

Can you please confirm this?

I am trying to remove a document via http://www.couchbase.com/docs/couchbase-sdk-php-1.1/api-reference-update-delete.html#table-couchbase-sdk_php_delete.

the code snippet :

var_dump($CB->delete("DOCUMENT_UUID"));
The output coming as
string(1) "0"
But data is getting removed.

And when the DOCUMENT_UUID is not present, its returning
bool(false)

In PHP most of the cases 0 represents False. :(
Like

if(0)
    {
    // This not happen.
    }
if(false)
    {
    // This not happen as above.
    }

Is that it supposed to do?

Can somebody confirm this?