I had a similar experience with a horse that, to my knowlege, had no
hobble training whatsoever. I was riding this QH mare in the woods and
asked her to step up to a tree so that I could read the sign posted
there. After I had read it, I asked her to back up. She started to, but
then hopped a bit and stood still. I looked down and saw some barbed
wire that had been hidden by the undergrowth wrapped about her ankle. I
got off and unwrapped the wire with her standing stock still the whole
time. She never even got scratched!
This is the same mare that grew to be absolutely obnoxious and dangerous
to me--dumping me (on purpose) every chance she could get. She even
PURPOSELY stepped on my toes one day as I was saddling her and WOULD NOT
get off, no matter how hard I pushed. In fact, she pushed back and
managed to knock me down while still standing on my toes. It took 3 men
to get her off me! (My toes were broken, of course.) I finally sold her
to a man who absolutely LOVED her! He ended up selling his other horse
and keeping her. I later ended up with my jewel: Silverado.