Is there any reason that a password change delivered into an AD Domain
via Quest synchronization tools should NOT be intercepted by the NetIQ
Password Synch filters and processed in the same way as any other
password change?

I'm not asking for reasons why password synch might fail... I'm asking
if there is any reason, in principle, why an AD Password change made via
Quest might be interpreted differently than an AD change made by a user,
or by an admin in ADUC.