I have seen and been taught conflicting ways to tie a rope halter onto a horse. I think there are at least three ways it can be done.
Here are two videos showing what looks to me like two different ways. The way I've been doing it, is how the woman says is wrong. Ok. I wonder, is that wrong? I had been told you want to do it so that if the horse pulls back it doesn't pull into a knot so tight you cannot reloosen it. But, to be honest, I am now not sure which way is correct.
A. Go through the loop, and back through the loop knot is tied ON the loop
And C. (and I don't have a video of this, so maybe it IS wrong)
You go through the loop but tie the knot abot the loop