I had two scenes I once managed to get, but never have been able to accomplish again.
One was where, I rattled the spurs on my boots to make the horse rush the man at the beginning.
And another was where I got struck by lightning.
If someone could help me figure out what I need to do in order to accomplish those two things I would be much obliged.
Lightning- you need to be Religious, so say your prayers as directed in the opening scenes. Then ride up into the mountains later when the storm starts and the option to dare God to smite you should be obvious. Not sure about the other thing.
I think you can also be struck by lightning if you aren’t religious 
You just gotta decide to start racing back down instead of dismounting from your horse and lying down on the ground when in the mountain.
Getting struck by lightning is important to save a witness in the Fake Marshal Steel chapter 