Strange problem

gistfile1.aw

// In my controller :

/**
     * @return array
     */
    public function logoutAction()
    {
        $this->getUserService()->logout();
        return $this->redirect()->toRoute('home');
    }

    /**
     * @return UserService
     */
    protected function getUserService()
    {
        if (!$this->userService) {
            $this->userService = $this->getServiceLocator()->get('member.service.user');
        }

        return $this->userService;
    }

Where logout :

/**
     * @return void
     */
    public function logout()
    {
        $this->getAuthenticationService()->clearIdentity();
    }


Where getAuthenticationService() :

/**
     * @return AuthenticationService
     */
    public function getAuthenticationService()
    {
        if (!$this->authenticationService) {
            $this->authenticationService = $this->serviceManager->get('common.service.authentication');
        }

        return $this->authenticationService;
    }