He's been using that lvl 51 M-Venusaur in the same box spot from the first episode he started using it. IMO he wanted to falsify the damage calculations since the beginning, since we can easily see HP Evs from videos, giving some infos to a follower that he's potentially going to meet at important events. I don't blame him if he's doing this. Top players should't reveal their EVs because it's so easy to answer to given numbers.
@edit: not in the same box spot everytime but still lvl 51
@edit: not in the same box spot everytime but still lvl 51