I've seen a lot worse looking stump's left in the wood's by people who cut trees every day.
In my opinion your back cut was a little high. In the video I never saw you sight the tree, guessing & hoping is a bad habit to get into.
I think that while you're learning the basics on small trees, you'd do better to cut straight into the "face cut" rather than dogging in and rocking the saw so much. If you're going to dog it in, then set your dog's and bring the bar around untill your sights are lined up with the target. Make it a deliberate motion, rather than back and forth.
The tree's down, no one is dead, and nothing is crushed. I think you did pretty good.
Andy