Javascript error in IE8 when in bullet list

When a user attempts to exit a bullet list in IE8 either by using toolbar or Ctrl + Shift + B, the cursor returns to the end of the previous point on the list. (Separate bug for that linked to this issue).

The user can exit the list by hitting [enter], however, this results in an extra line between the list and the subsequent text.

If they happen to attempt to exit the list by hitting Ctrl + Shift + B and, then, in frustration, hit [Enter] to exit the list and type text, a "'nodeType' is null or not an object" error is thrown when they start typing the subsequent text. Not a great workaround