You have to remember that all aircraft can stall if the aerodynamic conditions required for doing so are met. All wings have a CLmax and associated AOA that, if they are exceeded, will result in a stall. The A320 and other FBW airliners are protected in that the flight management computers won't let you actually stall the aircraft because they have an AOA limit which they will not permit the pilots to exceed. However, in the event of a system failure, freak windshear or erroneous data from the air data system, you can lose that protection and a stall can then occur.
The key with FBW aircraft is knowing exactly how the flight control laws work in normal, degraded and failure modes, and understanding which modes,failures or combinations of such will degrade or negate the AOA limit protection.