I had my young French Alpine buckling in my main pen the other day. He was following me about as I did chores. My twin miniature does born last august came over and started fussing over him - hackles raised, bug eyed, etc...
So, I made a snorting noise and threw my hands up in the air, stepping quickly towards them. One of the does - my butcher doe - ran away, the other FAINTED dead away just like a fainting goat. Fell over and everything. I didn't get her to fall over again, but I proceeded to pester her into stiff back legs.
A good friend of mine has fainting goats, so I know what a fainting goat 'faint' looks like.
Still today, when startled by the whip during feeding, she ran with the stiff-back legged fainter 'hop'.
I hadn't noticed till now because I hadn't thought of trying to faint any of my miniatures - as far as I know, my miniatures have background of mainly pygmies and nigerians. It's impossible to say if the myotonia anomaly just popped up, or if they have fainter in their backround somewhere... either way, it's odd!