I know from a former employee that Amazon is or was a very Perl centric IT shop. Not only could there by a keyword mistranslation, but there could also be a Regular Expression failure that turned a minor metadata mess up into a full fledged fiasco. I can totally see this happening from my own experience trying to apply changes to a great many records in production databases. Between that and an expression that's one character too greedy, you can match way more than you intend in any filter.