At least it is a easy fix. Can't tell you how many times I have done this. I really watch it now but when you are quilting you don't even think about it.

I've done that a time or 2 myself. So annoying.

If you're quilting on a home machine you should be able to reverse that extra stitch by rotating your hand wheel backwards (away from you) so the needle pulls back out of the extra stitch. I often use this trick because I'm always overshooting lines when I use my walking foot!

Good job.....