I hope you were able to finish your blanket. Did you sew binding around the edges?
I was going to suggest making your first round of sc edging into the front-loop of the stitches on the blanket ends. Then doing another round of sc as normal. These two rows would have covered up those loose loops. If not, you could have made a third round of sc before beginning your pretty edging pattern. Yes, the loose loops would still be visible on the wrong side of the blanket, but with the yarn edging behind the loops, they would not be noticable.
How did it happen? I think that you may have crocheted into the back-loop of your chain when you made your first row. This might be why the loose loops were so loose. For your next project crochet under both of the two top loops in each chain. You could also use a smaller hook if you chain loosely. I need to use a larger hook.