This is basically what watching the corporate media and posting on social media does to people nowadays.
I was involved in a real life version of this at work a few weeks ago.
We had an ongoing problem at work that I had not yet been involved in, so I was asked to blindly come to my own conclusions, as to not be influenced by everyone else's ideas. (Bear in mind that when I talk about ideas and conclusions, I am talking about very tangible things with very definite consequences etc. , not opinion, subjective, or statistic based things.)
I did so; and came up with an unpopular conclusion (even I didn't like what I had suggested), but had proven to myself why it must be so.
"Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth."
A meeting (off the books) was held with all the big fish at work physically present, including a couple of outside agencies representatives (probably 12 total), and 1 very, very, well payed, and highly regarded expert on the end of the telephone.
I was not specifically invited, being a relative small fish, but was told by one guy higher up (X) to just turn up anyway, as I was the only person to have had an in depth, unbiased look into the problem so far (people had looked into the problem already, but more off hearsay and assumptions rather than hard fact).
The impossible but popular conclusion (and therefore solution) was immediately discussed around the room, with everyone but me and X blindly agreeing. The atmosphere seemed to become one of back patting and general smugness that all the big boys were in agreement.
I announced why this could not be the case, and the room came around to my explanation, until one of the expert customers present threw in a curveball that I was not prepared to answer definitively with the information I had in front of me (I knew for fact what they were saying was wrong, but had not expected to have to prove such during the meeting, as I didn't realise any customers would be there chucking such wild curveballs).
Immediately all the bigger boys (bar X) turned straight back to the warm fuzzy explanation that they could all agree on. At which point the expert on the phone jumped into the agreeing group, which in turn immediately made the group believe in their idea more so.
In the meantime I hopped on the computer quickly and gathered the evidence to bat away the curve ball. During this time; the room was now discussing the plan of action with the expert.
Having gathered evidence; I interrupted the discussion to express how adamant I was that everyone else was wrong. The expert on the phone responded by saying that his colleagues sat next to him were also in agreement with the room, and that he is incredibly experienced in the field (that cannot be denied). I responded that I have the hard evidence on paper in front of me, and apologised that his mates and vast experience could not convince me otherwise unless they could tell me why I was wrong.
They could not, and even did not, try to refute what I had presented. The room went back to before, so I hopped back on the computer and gathered every little shred of evidence, no matter how insignificant it may seem.
The meeting finished during this time, at which point the biggest boys split off into there own meeting about how to proceed, which I again butted into and showed the catalogue of evidence. Only one of them (Y) let go of the warm fuzzy feeling of having an expert agree without evidence, and asked me to put down everything I had said on paper.
Once I had put it down on paper with my name and signature, it became the only course of action available unless someone else put down on paper why I was wrong. With no one willing or able to do so; the job was put on hold.
Y then sent of the official support request to the expert (he was expecting to be able to respond as he did in the meeting) citing my evidence. Low and behold a week later, now that big money and potential legal ramifications are on the line; he eventually agreed with my conclusion and suggested my course of action.
Take what you will from this story, but try and imagine who could be in what position in the video, and how the video could then represent different parties in this Markle discussion. You (anyone in the thread) may not change your mind, but I'm sure you will be able to see how some people can have theirs changed for better or worse.