Wow, I am so sorry that you had such a horrible thing happen to your quilt at your local LA. I haven't had that happen to me on any of my customers quilts, but after reading this I will definitely be extremely caution of long threads and needle positions. I am always watching for those but now I guess I am a little more paranoid that something like this could happen. Hopefully, your longarmer will do right by you and help correct the problem. But I do agree she should have been upfront with you and told you about the problem. The last thing I do before sending back a customers quilt is take pictures of both sides and check for anything that might need attention.
Good luck,
Sherryl
Candlequilter