It's a trait of sociopathy (psychopathy?), I think. One tends to align oneself with the views of the other person (aka lying). And to survive a demanding role that requires one to form and hold and justify one's own opinions, he probably takes the lazy route and keeps the last persona until his next mental reset.
He is an imposter in his own mind, and we know it.
With apparmor, you could enable and disable profiles that could restrict access to files and paths by name.
For network traffic, it's possible to use dnsmasq to blacklist or whitelist some domains.