I think what you are saying is only true if you insert at the end of the ArrayList, (or at the beginning if you have one which leaves open space at either end)

I think what you are saying is only true if you insert at the end of the ArrayList, (or at the beginning if you have one which leaves open space at either end) If you insert into arbitrary positions, or the front of these particular array lists, it will be O(n) even ignoring the growth issue, because every element has to be copied over 1 spot.