Greg Ward notes on the JPython list:
Looks like I've found a definite bug in jpythonc -- unreachable Python code compiles to unreachable Java code. Here's a simple example: [..] Yikes... does this mean that jpythonc will have to analyze Python code for reachability? Is this even possible? Guess the answer for now is, "Don't do that!".
This is another sort of warning that a checker could do in the core which could catch some errors. Not sure that it makes sense to try and find all the cases that an arbitrary Java compiler could find, but presumably Greg's original code which led him to the jpythonc bug find had a plain-old python bug in it? Did Aaron's pylint find any nonreachable code?