Not really. Deffering to someone with expertise and allowing them to oversee and organize an effort pertaining to their specialty doesn't necessarily mean that you're forming a hierarchical system. If people voluntarily elect to listen to this temporary leader's advice in order to better achieve their collective goals, and the leader doesn't have some mechanism to enforce their wishes, then the leader's station isn't higher than anyone else's. If the process is fluid, like with the sheep in the article, then it's simply a matter of people choosing to give someone increased capacity to manage the group while their knowledge and experience is relevant before shifting that limited authority (distinct from power) to someone whose abilities are more relevant.

While commonly characterized as being chaotic, anarchism doesn't require a total lack of any structure, order, and/or organization. The main caveat is that any system of organization is a matter of voluntary association, and that anyone in a leadership role isn't granted undue authority or presumed inherent legitimacy and the ability to impress their will upon others.