I have not seen the behaviour like this myself, but I have heard about one such case already. I agree with the second post in MSDN that this may be caused by pending NBL’s in underlaying NDIS miniport driver. Have you tried to update your WAN/LAN drivers? Which exactly causes the hang?
One possible option can be disabling network interfaces prior to LWF driver uninstallation. It can be also done from command line using devcon utility like described here http://wlanbook.com/enable-disable-wireless-card-command-line/