That doesn't sound very smart.... I'd say keep the horse from rearing in the first place (obviously totally different with a serial rearer). Not really a fan of the first video, the "correction" wasn't well timed and there are other (better IMO) tools to use to make a rearer stop.
I don't see how anyone overreacted to the video, it is a clear case of abuse and cause for some outrage among educated and caring horse owners. If you saw someone beating their child in public because they ignored it and it got too far away from her and into trouble, would you not be a little outraged yourself, having seen that is was clearly their fault the incident happened in the first place?
Now I am not comparing horses to children, but my point is that when the person is clearly at fault for the undesirable behavior but takes it out on the subject in an abusive manner, though the subject is only the victim in the first place, it is IMO cause for a little outrage...
What I find interesting is that the OP never offered any form of explanation/excuse. Has she left due to embarrassment? Did she really think we would be as amused as the person filming? I'm really puzzeled by her intentions, whatever they were.
Didn't watch the second video but was shocked by the first one. The rears were caused by the rider being too harsh on the poor thing's mouth. Smacking a horse once it has come down is stupid as it reinforces the idea that rearing is acceptable but coming down isn't. You could see where the horse was going to rear as it slowed right down, if her leg had been kept on the horse wouldn't have reared. I feel very sorry for the poor horse.
The OP is not the one on the rearing horse, she's the friend or something. If you click the link at the top of the video, it takes you to the video on youtube and in the comments the OP is defending the rider (her friend)