Denti,
With regards to "it" being an autoflight thing and not an FD thing - the flight director is the visual depiction of what the pilot should do to follow the same path as the autopilot would follow.
So, the FD would have seduced a slavish follower down the same primrose path to a stall. The only giveaway would have been the removal of the pitch bar from the display - and an Airbus would also have done that (re. the AF447 report, FD disappearing and re-appearing)
As far as autothrust is concerned - if you descend in FLCH and do not follow the FD pitch commands (such as during a TCAS CLIMB event), the autothrust will not increase thrust to keep speed constant, it will still indicate FLCH or THR HLD in the FMA (it "thinks" that the FD pitch mode is taking care of the speed).
A problem noted by the Canadians was that pilots routinely do not know all the possible autoflight/FD symptoms, such as diasappearance of bars, amber lines through FMA modes, etcetera, which may also differ from mod to mod status, because one "never" operates on those edges of the envelope.
However, abiding by the simple rule, if the aircraft does not do what you want it to do, grab control (physically do it yourself with stick, rudder and throttle) solves all problems.