Presumably the same distinction would hold true with respect to casting Fling normally and casting Fling during a resolving Expertise? eg. Kari Zev's Expertise

ie. sac a non-token creature casting Fling normally, opponent gets 1 zombie
sac a non-token creature casting Fling during the resolution of Expertise, opponent gets 2 zombies

Edited Todd Bussey (May 11, 2017 05:56:24 PM)

If your opponent controls Anointed Procession and Kalitas, Traitor of Ghet, and you sacrifice a nontoken creature to cast Fling, they will only ever get one zombie token, regardless of when or how you are casting it. No matter whether you're casting Fling normally or casting it during the resolution of another spell (such as an Expertise), paying Fling's cost is never an effect, so Anointed Procession can never apply to it.