I was under the impression that the Coriolis effect was almost completely negligible in small-scale systems. Similar to how it isn't actually responsible for water's rotation around a sink or toilet (they're actually designed that way), the curve of a frisbee is almost exclusively determined by the angle it was thrown at, and from which direction.
It's one of those bad, only 1% true explanations that caught hold in popular culture and won't let go. Similar to how it's still taught in lower-level science courses that oil and water don't mix due to density, when in actuality it's because of the polarity of the molecules.
Remember that the Coriolis effect is nothing but the difference in the speed of earth's rotation across the 11 inches of the frisbee.... that's an infinitesimally small amount. It's not going to affect anything at the scales we're talking about.
http://www.scientificamerican.com/ar...site-direction
http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html
http://www.snopes.com/science/coriolis.asp
http://science.howstuffworks.com/sci...t-baseball.htm