He isn't going to provide you an example because there is none meaning full in production. REST uses HTTP because it makes no sense to use it with anything else. REST only makes sense with HTTP. With another socket protocol, there is no need to bother with headers and co.
You're right, there are no other protocols at nearly the scale of HTTP that use REST. I was just pointing out that REST was not strictly associated with HTTP in Roy Fielding's definition. If you look at my other link (Richardson Maturity Model), you can see that RPC-over-HTTP is vulnerable to same criticisms in the OP's link. Hence, I think the issues discussed in the article don't singularly apply to REST.
