To be fair, it was the first season and there was a lot of weird incongruities in the animation. Remember Ms. Botzcoski and her almost unnaturally smooth animation?
https://youtube.com/watch?v=K1N-1C4cqEQHell, Beavis and Butt-head had the same problem with a lot of the early episodes, for instance the scene where Principal McVickers starts drinking a bottle of Old Crow in his office after forbidding Beavis and Butt-head from laughing. Sadly I can't find a clip of that scene, but it was really poorly animated by comparison to later seasons. Sometimes it takes awhile to figure everything out. Usually by the second season the animators have had enough practice to accomplish a more consistent animation style.