You are absolutely correct. If you deselect LVL CHG you FD pitch bar will disappear, because you are deselecting your pitch mode, NOT your speed (autothrottle) mode. Ie, you are pushing the LVL CHG button, not the SPEED button.
LVL CHG is a bad example, as in this mode the autothrottle will RETARD and ARM itself automatically. Imagine a manual FD ILS, deselecting speed now will deselect the autothrottle only, it will not remove the pitch bar.
[This message has been edited by ManaAdaSystem (edited 06 September 2000).]
[This message has been edited by ManaAdaSystem (edited 06 September 2000).]