To demonstrate my point, try writing the following into C.java:

public class C { public int foo() { return 1; int b = 1 + 2; } }

Then compile it (javac C.java). You will get the following:

C.java:4: unreachable statement int b = 1 + 2; ^ C.java:5: missing return statement } ^ 2 errors

Therefore this code is not compileable, thus telling us that the initial code blob could never have run in the first place.

I'm not sure why the decompiler returns non-compiling java code, I just know it does.