Difficult day with Billy

Morning session today as I soon have to go to work. Filly a bit brighter and putting more weight on her bad hoof, so pleased with that.
Went to play with Billy, taking a few cones along. Set them out in the field to see what he would make of them. Well, getting him to touch them was not a problem. He came straight over and started playing with them.
I then put the halter on and we started playing. I find it so difficult to find the middle of the road balance of enough pressure to motivate him, enough time to let him react, and slightly too much pressure which makes him go really right brain extrovert, and threatens to give me more rope burn. When I get it right is feels so good, when I get it wrong it's like a small nuke going off. The trouble is that I have learnt enough now that I can't blame him for being "naughty", but have to blame myself for being un-savvy, and being a male that hurts the pride !!
One of the biggest step forwards in my Parelli journey occurred early on when I not only understood, but really "internalised" the fact that a horse CANNOT BE NAUGHTY. Any behaviour that looks like "naughty" is just a natural reaction to either a stimulus I have caused, or an external one, such as a bag flying past. Horses can only act according to their instincts. To be naughty would suggest that they have a very high level mental capacity which let's them predict how I would perceive an action they make. To be naughty you have to be naughty to someone. Technically this is called "Theory of Mind" and horses are nowhere near having that. It is possible that a few apes and dolphins do, but horse no.
This of course leaves me with the realisation that undesirable behaviour is my fault. Either it is an a)inbuilt reaction that I have so far failed to modify, or b)it is a reaction I inadvertently created. This leaves me with nowhere to hide intellectually speaking.
I am hoping that today's problems where mode a) and not mode b) but time will tell I guess...