I would be surprised if a Japanese reviewer had a stolen sample, given:
a/ how tightly enforced IP laws are in Japan, and...
b/ the general attitude from Japanese fans towards intellectual property
c/ how strict TakaraTOMY are towards any potential IP infringement

I've seen Japanese fans criticise people if they so much as fail to give proper credit for the source of images.
Glad to hear that the toy was legitimately obtained.