Pretend chokes
The video is of a lame, contrived demo. The "choke" in it is not performed effectively. It's a farce of a choke. The reason this strutting bodybuilder is "immune" to the choke is that it's not a legitimate choke in the first place.
If you know someone who thinks they can't be choked, I think Marcelo Garcia would be interested in testing that hypothesis:
Stephan Kesting: Have you ever come across someone whose neck is too big?
Note, by the context of the conversation, Stephan means "big or strong".
Marcelo: No.
SK: Not so far?
MG: Until someone proves, like, oh, you can squeeze my neck and I won't tap, this is working for me.
Everyone can be choked.
So far, everyone who competes has shown themselves to be chokeable. Jon Fitch was notoriously resistant to being choked out...until he was guillotined into unconsciousness by Josh Burkman.
Strong necks can resist poorly-applied chokeholds and can, to a minor degree, prevent the attacker from getting into position for a good choke. But so far, everyone has proved to be chokeable. People can have good choke defense just like they can have a good guard, but so far no one has shown themselves to be "immune".