ArrayList code last_index issue - Section 9.2

Chapter 9, Section 2: Python Lists Revisited

The last_index in this code is tracking one position past the last item in the list.
It starts pointing to index 0 in an empty list.
Then, let's say we add 1 to a fresh instance of ArrayList, it will be the only (and also the last) item on index 0, but last_index will be 1
Up to this point, it's not a problem, but could cause problems when trying to pop an item from the list

class ArrayList:
    def __init__(self):
        self.size_exponent = 0
        self.max_size = 0
        self.last_index = 0
        self.my_array = []

    def append(self, val):
        if self.last_index > self.max_size - 1:  |\label{line:lst_arr_size}|
            self.__resize()
        self.my_array[self.last_index] = val
        self.last_index += 1

But then, there's a problem on this listing:

def insert(self, idx, val):
    if self.last_index > self.max_size - 1:
        self.__resize()
    for i in range(self.last_index, idx - 1, -1):  |\label{line:lst_arrlistins_range}|
        self.my_array[i + 1] = self.my_array[i]
    self.last_index += 1
    self.my_array[idx] = val

Let's say we have a list [1,0] with max_size == 2. According to the first snippet, after appending one item last_index == 1. If we insert anything, the first iteration on the loop will try to access the array on index 2, which should cause an IndexError