Author here. Ah, that makes sense. I always took it for granted that such a scenario of everything hashing to the same bucket wouldn't happen, but I understand

Author here. Ah, that makes sense. I always took it for granted that such a scenario of everything hashing to the same bucket wouldn't happen, but I understand now that in such a scenario it would take linear time, which means that technically the _worst_ case is O(n). However, I don't see that this influences the main point of the post. In practice, hash collisions are extremely rare, which means that the linked list inside the array slot is going to have few elements, and so we shouldn't be looking at the worst case time complexity of that linked list.