Just found by accident, don't know the side-effects.
~ li 161:
function get_the_mediatags( $id = 0 ) {
//[alx359] fix incorrect quotes
//return apply_filters( ‘get_the_mediatags’, get_the_terms( $id, MEDIA_TAGS_TAXONOMY ) );
return apply_filters( 'get_the_mediatags', get_the_terms( $id, MEDIA_TAGS_TAXONOMY ) );
}