There are various types of binding and printing errors, both in the Netherlands (Douwe Dabbert) and in Spain (Bermudillo).
Examples include: the wrong cover for the intended album, or the wrong spine, or incorrect printing information, or incorrect or no mention of the year of publication, or pages not in the correct order... Sometimes some of the pages were removed from one album and added to another.
When such an error was discovered, most albums were either destroyed or manually dismantled and re-glued. This depended on the number of copies that were incorrect.
A number of incorrect copies always slipped through.