Just shows that lintels and RSJ are just health and safety gone mad.
I tried something similar removing a wall between an integral garage and a kitchen. There was an air gap above the wall and the wall was made from fire blocks laid on their side (like breeze blocks on steriods).
I knocked two complete rows out of the bottom of the wall and it just hung there held in place by the side wall tie in.
I used an angle grinder to cut the blocks away from the wall and it still didn’t fall as it was just wedged in place between the side walls.
I then had to bow the middle out of the wall so it would collapse into the garage. I was quite nervous and it probably looked a bit like the guy in that film but I couldn’t think of another way to do it.There was a section of concrete wall just wedged into a gap but not supported by anything. IT is extremely hard to break concrete blocks that are laid on their side btw