According to the code you shown above
use Module;
fun1;
fun2;
fun3;
fun4;
perl will say error on fun3, that 'undefined subroutine called', because it is coded in EXPORT_OK, so how you have got the output?
fun1
fun2
fun3
fun4
Vivek
-- In accordance with the prarabdha of each, the One whose function it is to ordain makes each to act. What will not happen will never happen, whatever effort one may put forth. And what will happen will not fail to happen, however much one may seek to prevent it. This is certain. The part of wisdom therefore is to stay quiet.