Volibear... what?

Ok, so I know Volibear isn't all that hard to deal with specially if you have Rylai's as a Vladimir but something has been bugging me and I am not quite sure what is going on here.. When I am being chased, specially early game where I still don't have Rylai's and Volibear gets extremely close you know he is going to flip you over to 2v1 you with the laner, if being used as Jungle that is, the thing I think is a bug this that I go into pool and he flips me over anyways, like I see the massive patch of blood just flying over his head and I am just dumbfounded as to how... Does Volibear's move actually count as a hit moments before the animation actually plays? Because I wait until its certain he will hit me unless I pool to not waste it but I can see my pool animation go down before his flip animation starts and... idk, help?