I'm not tryimg to brag, but I watched 4 of those lameness labs, and was right on 3 of them, with the forth being a trick question, since the horse was not lame at all.
The chestnut in your second video is clearly lame in front.
but, YOUR horse, I still think it is right rear. your video is a WALK video, so will have to be judged differently. Look at the VERY first couple of strides he takes. look at how, when he pushes off from his right hind, he limps , and uses his whole body to absorb the movement.
A trot video could change my opinion, but from what I hae seen, I still say right HIND.