Gorramit! The more I thought about that baggy heel, the more it bugged me. I briefly considered frogging the whole thing and starting over again. I yanked out the needles and pulled it on, the leg's fine but the heel's too wide. Okay, leave the leg alone, frog back to the last round before the heel. If this were stockinette with this yarn & needles I'd have 80 sts around at the ankle and do the heel flap on 40, I've got 60 across the back now. Aha! The last round before the heel was knit even, I'll just decrease every other stitch (k1, k2tog) across the back of the sock to bring it in to the right size. There were increases when the zigzag started to make up for it drawing in so much, so decreasing when it switches back to a larger gauge section makes sense.