Was he in the act of shooting?

[Freddy]

Originally Posted by scooter2

I've been in a couple of situations where I had to basically "predict/guess" whether or not the player was indeed attempting to shoot (or pass) when he was fouled. I'd like to know how veteran officials handle this situation. Will it ALWAYS end up being a judgement call?

I'm not sure about your "attempting to pass" situation, but on your "attempting to shoot when he was fouled", this might be to the point.
This is why I am trying to stamp out the all-too-cool-to-call phrase "On the Floor!" with me myself and my partners. True, a fouled player may not have yet become an airborne shooter, thus is still "on the floor", yet by rule he may deserve two shots at the stripe if his completed try was not successful if he was fouled.
Seems it's not so much a judgment call as it is a matter of identifying when the act of shooting begins. According to 4-41-1, "The act of shooting begins simultaneously with the start of the try..." and 4-41-4, "The try starts when the player begins the motion which habitually precedes the release of the ball."
A somewhat helpful site (to be used with caution, as with anything) which offers visual examples may be accessed at: How to officiate when a player is shooting in basketball | Video « Wonder How To (Caveat: this site features FIBA content and it sometimes has some erroneous video illustrations on some matters, but at least it served as a resource to begin me thinking about the topic at hand and prompt me to further exploration; I wish the "Officals' Ed." section of the NFHS website had a good set of video clips on this topic, or maybe I missed them there)
Judgment call? Perhaps. Yet there are some concrete indicators of how that judgment should be made more confidently.
Hope that helps you on a topic I'm continually studying, too.