Pro tip: Leaving heel long on trims cuts down on soreness
Most farriers trim heels real short, saying it's best for balance. I started leaving more heel after seeing horses limp post-trim. Now those horses walk out fine and stay sound longer. It goes against what many teach, but I stand by it. My callbacks for soreness have dropped big time.
Did your buddy notice if the farrier took any off the toe too? I had a friend with a paint who was sore for days after trims until her farrier left the heel alone and just shortened the toe a bit. That mare started walking out sound just like your buddy's horse, no more limping or looking at the farrier like he was the devil.
How much heel did the farrier leave? @bell.emma, that's key since over-trimming the back often causes soreness. I've seen horses walk fine right after a trim when the heels are kept up.