"With ME neutralized, the MEI interface disappears from the PCI bus, and the integrated NIC ceases to work, but will resume to work after a reboot."
Why would the NIC only break once after the ME is neutralized? The system is started from a fully powered-off state after the ME firmware is updated. Maybe the NIC has some sort of non-volatile state that gets updated when the ME fails to initialize, and then the NIC starts working again. That's the most complex explanation so I thought it unlikely, but I'm happy to hear more from someone who has actually neutralized their ME.
After a reboot, the NIC starts without the ME ever taking control of it, so it works.
It's not strictly clear to me, but reading through what they're doing, the ME isn't re-engaged or its unclear how it recovers itself.
Unless the ME is operating with a recovery binary somewhere that isn't covered by Nicola's neutralizer and the subsequent flashing, I don't think it comes back in to normal operation.