Can there be sensible choice behavior that violates the Weak Axiom of Revealed Preference?
I think that your example relies on a misunderstanding of the meaning of the choice function. $C(\{x,y,z\})$ does not contain the elements that the decision-maker would choose simultaneously if he could. He is only allowed to select one element at a time (otherwise, why not consuming all three items ?). Therefore $C(\{x,y,z\}=\{y,z\}$ does not mean that he selects both shoes. It means that, if you ask him to choose one element inside $\{x,y,z\}$, he might either pick $y$ or pick $z$, being indifferent between the two. In that case, your story would not make much sense, since the value of a single shoe would be the same in both choice sets.

Regarding your question, there are some well-known violations of WARP that rely on behavioral biases, in particular the attraction effect and the compromise effect. These expressions describe situations where the comparison between two goods is affected by the nature of a third (unselected) good in the choice set. You can easily find some references (experimental evidence, models) on these phenomena.