Chapter 3, Mutating while Iterating error?

Books Data Structures and Algorithms in Kotlin
1 
override fun remove() {
  // 1
  if (index == 1) {
    list.pop()
  } else {
    // 2
    val prevNode = list.nodeAt(index - 2) ?: return
    // 3
    list.removeAfter(prevNode)
    lastNode = prevNode
  }
  index--
}

In step 1 the index should be checked for being 0 not 1.