I just recently finished quilting a lap size quilt and when I was getting down to the end on the border I realized I'd goofed up on the last one on the side where it meets up with the bottom border. Decided to leave it as I doubt anyone would really notice an extra line stitched. I corrected the digitized pattern for the twin lap quilt though.
I feel if its not that noticeable and if I don't mention it, no one will notice either. Of course I'm lucky enough that my recipents have no knowledge on what's what with quilts too.