I think a long armer should lay out all perspective quilts with the owner present. They are usually good but not miracle workers. It isn't fair to blame them for a top that has problems. I think LA should do this to protect their reputation and to discuss possible solutions. They should work out a price chart for any fixes that they attempt. If the owner just wants it quilted "as is" that should be clearly understood by both people.
A book made up for customers to sign for "as is" quilts may be good idea also. They should have a sample book of pictures of their quilting masterpieces as well. The LA then has some protection if an "as is" customer is showing everyone and making unfavorable comments. LA customers should also look through the persons work before leaving a quilt. Just my honest opinion, feel free to disagree.