I have a German instruction for the Dutch heel (I do not work this heel because I prefer the horseshoe heel). It's a little bit different than yours and I try to translate it for you:
[i]Knit until the middle, then: K2, K2tog, K1, turn.
Slip the first stitch, P6, P2tog, P1, turn.
Slip the first stitch, K7, K2tog, K1, turn.
Continue until all the heel stitches are incorporated[/i]
I hope this did help you a little bit.
Another idea: is your missing 5. stitch perhaps a stitch from the heel flap which has to be incorporated by the decreases?
Oh my God :wall: .... I know exactly what I want to explain - but I know it only in German :shrug: