I watched the video and did the stitch. The good news is that I see what you are talking about because I had the same thing happen to me a couple of times.
The bad news is that I was trying to do it right and don't know what I did that caused that to happen.
I think what is happening is that somehow that very end loop that actually connects to something right there at the beginning of the bunch of loops that you are going to make the elongated stitch from (this is after you have done the row where you did all the extra wraps and now you are going to knit across and let all the extra wraps fall off) doesn't get knit into. So the whole works isn't "saved" but just all falls off as a big loop. What we're doing to cause that I'm not sure. But be very careful on each stitch that you are knitting into the very end loop where it actually goes down and connects to something. I noticed that sometimes that part that needs to be knitted into isn't first in line for some reason. But I also tried knitting into something else there and that didn't make it fall into a big loose loop either so that doesn't explain it altogether.
Another thing to watch for is that after you have knit that end loop connecting thing and have a new stitch loop on the right hand needle that you hold on to the new stitch loop that is formed on your right hand needle with your forefinger of the right hand so that it doesn't fall off. I know for certain that if that falls off we get a big loop that is not knit and just hangs there loose. Maybe that was what we did wrong.
Let me know if your problem goes away.