Could you explain how it was possible that they misrepresented the duration of the boil-off period
I do not think it is possible that they misrepresented as much as you think. With very high foam level, they would have ended with dry cell much earlier, but that is not what the video show.
To illustrate my point, if F&P had 3 cm bubble layer it would mach their video better than if the foam level very very high.