hook_file_delete() called without valid $file object

while hook implementations rely on it, in case of filefield_meta it results in benign "DELETE FROM filefield_meta WHERE fid = 0", but in case of video module the result is #906262: All thumbs deleted without reason after Video creation, cck-6.x-2.9, filefield-6.x-3.9 & dev
To recreate:
1) attach filefield to any node type, with default settings (not required)
2) create a node without uploading any file, will get you following in node object

    [field_file_test] => Array
        (
            [0] => 
        )

3) delete node
filefield_field_delete_file() is called with NULL as first argument