Love the way Holmes gets off his horse, JB clearly knew how to ride... and then there's Watson bouncing around like a sack of potatoes XD Brilliant episode :D
3:50; old shoes, new nails. I know its a plot device but this doesn't make a lot of sense. Even if they get no wearing down, horse shoes have to be taken off and refitted every couple of months as the hoof grows out. For a hard up country dweller like Hayes, in those days, I think if would make sense to get as much use out of old shoes, the expensive bit, as possible and I doubt they spent much time riding or driving on tarmac to wear them out. The nails of course are new each time as they are bent round and trimmed off. So seems to me it would be the norm to find shoes refitted, and not a thing to send lightbulbs going off.
@wadyano the ruffian that works at the Fighting Cock in, the one who Watson didnt like when they met and basically threw the dinnerware at him was the one that made those tracks. He took the shoes off the horses and ran them all around the moors to disguise the tracks. The unshod horses hooves looked enough like cattle to throw them off until Holmes realized the horses were shod recently, with old horseshoes but noticed the new nails.