Ah, I love watching cross country videos! I don't think I'd ever have the guts to be actually ride cross country, but it sure looks awesome!
I think the sentiment of that lady at 3:37 is really awesome, that she's congratulating the horse for getting them safely over the combination. And I think it's awesome that that helped you see your relationship with Nelson in a slightly different light. =)
However, I have never seen a horse that actually enjoyed being smacked like that. I've seen tons of people just smack, smack, smack away on their horses and not one of the horses seemed happy. I actually cringe now whenever I see someone do that. My "trainer"/riding tips buddy put it to me this way (I used to be a "smacker"): She related smacking to another horse kicking or biting a horse in the field, and it makes sense to me. When I put all my strength into "patting" a horse, like that woman did, that isn't something a horse can recognize as a good thing since they've never experienced that kind of pressure when it means love. Also, what's another reason we might touch a horse on it's neck with that kind of force? When we're reprimanding it (hitting it for biting, what have you)! How's the horse going to know the difference between a "bad boy" hit and a "good boy" "pat"?
My friend recommended rubbing the horse on the shoulder as a way to say "good boy" since that can be related to two horses mutually grooming each other. I've been rubbing for a few years now and I can safely say, that even though it's less dramatic and "I'm telling my horse she's good"-looking, the horses I ride seem to like me better. Of course, that may be because I'm a significantly better rider than I was back when I was "patting" horses, I don't know.
But I feel better about it.
That was a great video, thanks for sharing!
And sorry for writing a novel... Haha