When using a trailer tie, attach the panic snap to the trailer. Use the bull /hook snap on the horse's halter. It may be a bit more trouble. But, imagine trying to reach the panic snap on the halter... When the horse is pulling away from the window AND throwing his head around. Imagine, the danger to yourself reaching through a window, toward a horse having a melt-down. And, if you somehow get to the panic snap, the horse is loose on the trailer.

If the panic snap is on the trailer... You merely have to reach up to the stationary snap just inside the window! PLUS, you now have a short lead line attached to the horse.

Anybody else with a safety tip ?

Good advice, I've been doing it the other way for convenience. I'll change my habits.

Bump...

Bump again. Was at a clinic a few weeks ago. The exact situation this applies to, happened. Luckily no one got hurt, a panic snap at the window would have been helpful.

Good advice.

We use the elastic short trailer ties with bull snap and panic clip for outside the trailer tieing. They have enough elastic for a panic and don't allow the horse to reach the ground. We have a young QTR horse that gets nervous occasionaly.
The panic end fits nicely to the trailer. And no worry if the knot is tied right

Never use an elastic tie with a hard (metal or plastic) snap on the end away from the horse. If the horse panics and pulls back and you release the panic snap it will spring back at the horses face. I know a horse that was blinded in one eye because of this. They do make bungee ties with Velcro attachments at the end away from the horse, these are much safer.