Wow! This subject really hit a nerve, didn't it!? This exact thing happened several years ago in a sewing circle I attended. It was sharing time and some courageously displayed their lovely quilt. Across the room someone made the comment that there was a mistake in the quilt. The creator said, ' I knew you would find my mistake'! I personally thought it was in very poor taste for someone to point out a flaw in front of the entire group!
For me personally, I would like to know 'privately'.. and in a nice way... most definitely NOT in front of other people.
I love the comment that every quilt has a mistake in it and the Amish actually purposely make a mistake. I guess that means we are all human and very much not perfect.