I'm not bothered by grey on a face of a horse that age. That's normal.
As for cushings, no indication of that - it shows even after clipping, affects musculature, etc.
Many times someone will get a horse with a huge long coat because it was out in a bad area, left wet and dirty, not given a lot of feed, it will have a huge coat - and at this age, the coat gets very, very long and wavy and doesn't always shed well (Even without cushings) - and they will clip it off, especially if it's very dirty.
There's a misconception that every bad coat on an older horse is Cushings - while it MIGHT be, it isn't always. Older horses get less efficient at digesting and warming themselves - they grow a lot of coat and it doesn't really keep them warm so they grow more.
I, in other words, have an elderly yak in my barn - normal thyroid, no cushings. When a kid came over and hugged his neck and screamed, 'he's so PLUSHY!' I knew I had an elderly equine yak!
I am bothered that a horse is shown on a video in deep soft snow, held in like that (that has NUTHIN' to do with being an 'advanced' 'dressage rider'), and shown in only 1 direction - BUT - these videos, guys, they are such poor quality most of these sales videos, the footing where the horse is being worked is so bad and uneven, the riding is so - ah - well - let's say most of these horses aren't being done any favors. Honestly with this kind of video, the only thing you can tell for sure is the horse has 4 legs.