Under the CFAA, it might in fact be illegal to randomize your MAC address depending on the terms of use for the network you are accessing. It is not illegal for this guy to access his home network in this way, because he owns the network. However, the danger of the CFAA is that it makes it a crime to violate user agreements - which can say anything that the network or site owner wants them to. It effectively allows anyone to author and implement their own criminal laws and have them be enforced by the full power of the federal government.
As for the wire fraud implications (which are separate from the CFAA), if you cause a false statement to be transmitted for the purpose of obtaining money or property, you have committed wire fraud and face a potential 20 year sentence. Spoofing MAC addresses to exceed access limits, for example, would qualify. You are causing your device to mask its true identity for the purpose of obtaining "property" that you wouldn't otherwise have access to.
As for the wire fraud implications (which are separate from the CFAA), if you cause a false statement to be transmitted for the purpose of obtaining money or property, you have committed wire fraud and face a potential 20 year sentence. Spoofing MAC addresses to exceed access limits, for example, would qualify. You are causing your device to mask its true identity for the purpose of obtaining "property" that you wouldn't otherwise have access to.