In that very blog you linked, if you look at the second bolded question (Q&A style format), you will see what I am referring to 
If I’m including an OAuth token, do I need to include a Client-ID?
If you are passing in an OAuth token, we will figure out the Client-ID for you.
There is nothing wrong if you choose to also send the Client-ID alongside the OAUTH, I was just letting you know that it isn’t required in that case