The thing is, any misbehavior should be treated as such or it will turn into a learned trick. Though there are some exceptions, I typically will discipline any bucking even suspect that the bucking is rooted in pain, because they should never feel like it’s okay to buck (or rear). It’s amazing how fast they can learn it’s okay to misbehave. I may end the ride almost immediately, but I will absolutely discipline the buck.
Just pulling his head up and continuing on clearly hasn’t stopped his bucking, and you need to address it in a much stronger fashion. He needs to clearly know that bucking is NOT acceptable, and your correction should be as big as they need to be to produce that result.
If as you begin addressing this he starts throwing bigger fits…well, I wouldn’t be surprised. You’ll be getting after him for something that you’ve taught him is okay. So expect some resistance as you try to fix this.