Someone tried to use this bug in ladder games. So it should be fixed asap.
Heroes: axe and morphling(with scepter), or 2*axe just for test.
Mophling use hybird to make a clone of axe,
1- If the clone casts berserker's call to enemy heroes first and then axe also casts it before the debuff ends, enemy heroes will lose control and attack the clone until one of both died.
2- If axe casts it first and then the clone , enemy heroes will totally lose control, forced to attack axe "forever", even if axe died(they will stuck there, wait for axe back to life and continue to attack. Unless enemy heroes died.)