If she got physically hurt and had to withdraw or performed poorly, it would not be a choke. Or if she played and just flat out got beaten by a better competitor it wouldn't be a choke.
Honestly, I don't really think she "choked" per se. It's not some horrible failure or anything. It just kinda looks bad on her. And it's kinda weird that people are so hellbent on squashing any criticism of her.
A star athlete pulling out of the biggest competition in the sport mid-competition, without any kind of injury, is weird and is just naturally going to be questioned. It's pretty baffling that anyone would think otherwise.