That has a lot more to do with mechanical sympathy, and awareness of when you've exchanged cleverness for complexity disguised as cleverness, than it does with knowing the big-O of operations on a datastructure.

What you want the person to identify is that they've made your simple iterative checkout process into multiple unbounded tree traversals with no circuit breaker.

Knowing that searching the tree is O(log(n)) isn't very helpful when your problem is an inability to identify that you've made (n) an unnecessarily huge problem space.