IN AND misplaced parenthesis bug

I was working to construct an SQL query to prevent draft messages from being moved to different folders. After adding the 'Drafts' folder exception I forgot to move the parenthesis. Here is the malformed SQL query that failed to trigger a syntax error:

SELECT me.id, fo.folder FROM messages AS me INNER JOIN folders AS fo ON (fo.id = me.id_folders) WHERE me.id IN('13515','13514','13512','13511','13510','13509','13507','13506','13505','13504','13502' AND folder!='Drafts');

This returned the messages in the 'Drafts' folder and I did not receive a syntax error. That being said, I don't want to rain on anyone else's parade if they have a legitimate use for the same general syntax structure. I figured, if there is no viable use-case then someone else might have this problem and could have been spared having their time wasted if they had received a syntax error.

For contrast, here is the corrected SQL query:

SELECT me.id, fo.folder FROM messages AS me INNER JOIN folders AS fo ON (fo.id = me.id_folders) WHERE me.id IN('13515','13514','13512','13511','13510','13509','13507','13506','13505','13504','13502') AND folder!='Drafts';