Binding off for scalloped edge?

I just finished my first lace piece/stole. It had a scalloped edge. When I did my bind off, the finished edge did not make a scallop! (I was soooo mad. Especially after all that hard work!) Can someone please tell me what I did wrong? I ended on row 8, did my bind off on WS, as told to do…I bound off doing all purl bind off, because the next row in the pattern is Row 1 (WS), which was purl all the way across. I was always told to bind off “in pattern.” Here’s the link to the pattern. I sure hope someone can help me. I’d love to try this again, but I need to learn hope to make a scallped edge/bind off.
Thanks so much for all your help…in advance! -Lee in FL (fllee)

You may have made the BO sts too tight. Do it again trying a larger needle, maybe a size 10 or 10½.