I had been told by a professor once that if the pull was very rapid, the momentum of the air would allow attached flow at an angle of attack greater than the stall angle of attack with (for a brief period of time) and, hence, a higher-than-normal Cl. That is one reason it's a very bad idea to check if Va actually works with an abrupt pull of the stick (yoke) as Va is a theoretical value determined with a load factor of (normal category) 3.8 g's and a "steady-state" maximum Cl.