I'm sure the other members will echo this thought... don't give up after a mistake and ride to get out of the class... if you want out, simply dismiss yourself rather than riding like you don't care. As a rider, you are at all times training your horse and yourself. Leave the mistake at the place it occurred and ride the rest of the course like it never happened.
That said, the thing that stands out on your rounds is your arms and when you are coming off the fence. Your elbows are constantly wiggling on approach and they seem pretty locked and stiff in front of you.
As you land off a fence, several times your hands did not follow the motion of your horse's head, causing her to yank it up. I'm not sure if this is what occurred on your dropped pole, but I def noticed it more and more after that point (I know you said to ignore that aspect, but it was a very telling aspect of your course).
If I were you, I would be working on a soft forward course, where your horse is between your hands and leg, not just in front of your leg... working on giving with your elbow, and having a more quiet arm and upper body.
If your horse says no, you either asked the wrong question or asked the question wrong
And God took a handful of southerly wind, blew His breath over it and created the horse