From a script, if x is a variable in the binding, calling x() appears not to try calling x's call method, at least in some cases. (It does work for closures, though.) The following example code illustrates the behavior fully. When running the code, it catches the MissingMethodException and print "oops – didn't try c1.call()".
If this is intended behavior, I'd appreciate an explanation. I apologize if this is known. I searched JIRA but didn't find anything. I suspect my indentation will not be preserved here...