Don't know what you saw as I was not there.
There is some evidence of 'energy flows' in the human body. I think it was Wilhelm Reich who first started researching it. I heard my professor in psychology mention it once in class, but he didn't delve deeper into it. So I don't know what research of academic level is being put out/has been put out.
I don't believe in mystical proportions of Ki, but I do believe that your body compusture and your outer looks can have an impact on an attacker. Psychology of the mind. Someone red with rage and under the influence of coke, stopping him with kaia, be my guest. Don't believe that it will work.
Then again, no everything in this world has been proven. So I just take a neutral stance on this one.
Pressure points on the other hand, now that's painfull. When I did hapkido (only did it for a couple of months), the teacher always did pressure points in class. I surely believe that when you touch the right spot, you can have a serious impact on the fragile balance of the human body. Pushing nerves always has an effect as I noticed when treating patients who had neurological pains. Some good (in the clinical setting), some bad (when in MA class).
But as still learning said: trust your gut.