Yes, I think lame. And that's beyond the peanut-pusher deadhead "jog"--is there supposed to be a hesitation between strides? Yikes. I don't see the same extension on both hind legs. I'm thinking favoring the right.
The horse looks lame in general, but around second 1:21/ 1:22 he takes an even more obvious lame step.
You know, I am a western rider, and maybe I just haven't seen enough of what goes on in english riding, but this is where I think english riders have it RIGHT. They actually want to their horses to move along with a little speed and impulsion. I don't know why western show people want their horses to move SO SLOW that the horse can barely maintain the gait.
But yeah, this horse seems to have an actual lameness. :(
Edited to add: If you make it all the way to about the 5 minute mark, the horse actually jogs out pretty normal. So is he still lame and I just don't see it now? Or did he warm out of it? Or is the short striding just due to the abnormally slow walk/jog he was doing at the beginning of the video?