The aircraft has been flying above the level flight stall speed and suffers "an inadvertent increase in load factor". This is the same thing as an inadvertent increase in angle of attack, which stalls the aircraft. Even if the aircraft is slowing down a stall at a load factor greater than 1 is still an "accelerated" stall.

Tip: One of the things that always gives trouble is the definition of all the stall speeds, Vs, Vs0, Vs1, Vs1g etc. Worth learning