This is why I strongley believe in the saying "any horse any day". You never know with a horse, that is why you have to maintain a level of respect between you and the horse, meaning the horse has to respect you also as the herd leader, and never think about challanging you for the spot. Doesn't mean you guys can't love each other and share affection for each other.
I usally have the horse tied up in cross ties so they can't get their head around, if I tie to a tree or such they are still up close enough not to get their head around.
He may have been irratated at the bites or still itching, but no excuse for biting you (the alpha horse). I will let my horse turn and see what I'm doing, horses are very curious animals. But if they get too close I'll gently tap them with my "boney" elbow. If they swing their head around in a fast agressive motion they get more than a gentle tap. If a horse bites me in the pinching manner they immediatly get a smack to the mouth. While I seen it twice one has never biten me in the way it was planning on killing me. Your bite sounds like it was more of the "let's see if I can advance in the herd" type of bite.
If you discipline a horse it has to be within two or three seconds of the action. You can't get bit and stand there for a minute in pain then go over and kick your horse. The horse will not relate you kicking it to the bite. It has to be a immediate reaction to the action. As I stated in another post, If I get bit, I smack the horse immediately in the mouth or end of the nose, that's the area that did bad, that's the area that recieved the discomfort. Again if you get bit and wait long enough for the horse to turn it's head forward and even pick up a leg to rest then hit it, your horse may think it got hit for resting a leg.
Both of these two cases where while handling stallions, but any horse any day. When I was in my late teens I work in a large Arab barn. A young man was leading out a 7 yr old Stallion, as he did every morning for a couple of years. Without warning the horse turned on him and removed his right breast to the bone and part of his shoulder. The other case was a 4 yr old TB stud, a young girl, in her early 20's, had just finished round penning this horse. as she was putting on the halter the horse grabbed her by the upper arm and picked her off the ground then threw her to the ground at least three times before others by her could get to her. A biting horse is not cute and you have to always be the one in charge and make sure they don't get to cross the lines you make.
Any horse any day
Alan