I answered your other post too, since I'm familiar with the pattern now.
If you knit something and just cut the yarn, and leave the knitted object on the needle, it won't unravel. In this case, you're going to knit into the earflap stitches that are on the needle. You will have a string hanging from where you cut the yarn, but that can be woven into the back of the hat later. Nothing will unravel.