Windzall
"Well, right before she was in the pen... as for what she ate..." The woman suddenly looks worried. "She ate the same thing as the rest of the pokémons... I need to check up on the others." She leaves without really paying much more attention to you. Without anyone to supervise you, you're free to look around the place.
Outside, you spot the clown you were talking to heading for the barn, probably to check on the pokémons' food. But seeing how the rest of the pokémons are acting, it doesn't seem there's an issue. In fact, they look far too tame for a rodeo, placidly working beside the other employees of the farm. You can't help but wonder if the bucking and jumping they do in the arena is more them acting than them trying to throw off their riders.
It easy to figure out where Matilda was before her rampage, just look for the broken fence. Next to the arena are a few small boxes where the pokémons waits for their riders, the 'bucking chutes'. The chutes are divided in three different sizes, to fit ponies, horses or tauros, or Matilda. Only one part of the chute was broken, with no real signs of damage on the other side... though Jake notices a small piece of glass next to the door.
It looks like a small tab that broke off from a larger item. Looking at the inside of the door, you spot a glass ampule taped to it that fits the tab you found. Unlike normal vials, it seems made to hold two liquids without mixing them. The content is gone, but one side still has a reddish tint, while the other has a blue or green tint. The way it was tapped, the ampule's top would have been broken by opening the door, releasing it's content.