I still see what you have described, to be a pressure-release system. Pressure does not need to be physical contact, just like the dominate horse in a relationship can simply give 'a' look at the submissive horse, and the submissive horse moves away. When the submissive horse moves away, the dominate horse doesn't look at him anymore.
So by standing in front of a horse, saying 'back' and waving your hands around a bit, that IS pressure. The horse is wondering what on earth you are doing and steps back. You then stop waving and give him a pat - release of pressure.
How is this, any different from any other pressure-release system?
Pressure-release does not need to be an escalation in pressure, there are many ways to skin a cat.
Some horses respond best to escalate pressure, others learn best if you ask, then back off, and ask again, like your own horse.
It is STILL pressure-release. I don't know of any single training method that does not use some form of the pressure-release system --- because this is what works for horses. They put some kind of pressure on one another, move away from the pressure, and then they are comfortable. You cannot ask a horse to do anything, without putting some degree of pressure on them. It is not possible.