We're working on the asumption that this is a throw-in.

I tend to agree with Mark essentially on the wording and the fact that it does specifically use the word TRY. If we are going to just assume that BI/GT applies to any thrown ball then the word TRY must be eliminated from the definition.

And just as my own little editorial, I'm against the wording that allows any THROWN ball from 3pt range to be scored. I think that this defeats the purpose of the definition and application of TRY. If A1 is passing the ball to A2 for the "throw down" and A1 is fouled while behind the 19'9" line should we start considering giving him 3 FT's for this. I think the intention of adding the "Thrown ball" provision was good, but creates alot of application controversy.

Your question is a bit different. In the BI situation we are trying to decide whether the RULES support a decision to award 3 points. It seems that they do not.
In your senario, the official first makes a judgment about whether the player who was fouled was in the act of shooting and then he refers to the rules for the appropriate penalty. Personally, I don't find it that hard to award only 2 FTs if you firmly believe the player was passing.
To sum it up, in the BI there is no judgment needed you simply follow a rule and do what it says, while in the foul case the official must make a judgment call about the play.