The spec for CopyOnWriteArrayList.subList(...) strongly suggests that
non-structural modifications to parent list (e.g. set(int, Object))
are permitted while a subList is active. In fact, this leads to
ConcurrentModificationException.
 
    * Returns a view of the portion of this list between
     * <tt>fromIndex</tt>, inclusive, and <tt>toIndex</tt>, exclusive.
     * The returned list is backed by this list, so changes in the
     * returned list are reflected in this list, and vice-versa.
     * While mutative operations are supported, they are probably not
     * very useful for CopyOnWriteArrayLists.
     *
     * <p>The semantics of the list returned by this method become
     * undefined if the backing list (i.e., this list) is
     * <i>structurally modified</i> in any way other than via the
     * returned list. (Structural modifications are those that change
     * the size of the list, or otherwise perturb it in such a fashion
     * that iterations in progress may yield incorrect results.)

public class Bug35 {
    public static void main(String[] args) throws Throwable {
java.util.List x
= new java.util.concurrent.CopyOnWriteArrayList();
x.add("foo");
java.util.List y = x.subList(0,1);
x.set(0, "bar");
y.get(0);
    }
}

=>
Exception in thread "main" java.util.ConcurrentModificationException
at java.util.concurrent.CopyOnWriteArrayList$COWSubList.checkForComodification(CopyOnWriteArrayList.java:1121)
at java.util.concurrent.CopyOnWriteArrayList$COWSubList.get(CopyOnWriteArrayList.java:1150)
at Bug35.main(Bug35.java:8)