I'm pretty sure she means that for a 5th ride and being completely unaccepting of the bit, there is absolutely no reason whatsoever she should be cantering already. She's just being set up to break down. Running around that hollow backed and evasive is only asking for injury.
Her back end is very steep and high, it looks pretty weird to me, but she might grow out of it? Even though this is only her 5th ride, I don't see the "talent", but the way the guy is riding her isn't doing her any favors. I'd probably rather see her on the lungeline to judge her natural movement. :/ They all look like dorks when you first start riding them, it's hard to judge until about 30 days.
I kind of agree there. She has 30-60 days on her currently. She said she looks really good now. This is the only video they have of her right now so she could be different, but I've not seen face to face yet. Posted via Mobile Device
If this was the guy doing the training, I would ensure a VERY thorough vet check of her legs and back to ensure soundness. She's at a very awkward stage and I would be hard pressed to get on a horse that is so angular and awkward in her growth. Her hind end is very weak and that's not saying it won't improve (my mare's hind end improved tenfold from 2 years old to 5 years old), but I would be wary about pushing that kind of work out of an unbalanced and still growing horse.
Just make sure you do your due diligence before signing anything (I assume you're looking to purchase her?)