Every scientist wants to make things go bang. But lesson number one in DIY science is: When the experiment starts to fizz, put it down and back away......
I think what they were going for was something more like this:
....OK, so that didn't go to well either.
Look: The basic idea is to rapidly mix baking soda and vinegar. Vinegar contains acetic acid, and baking soda contains sodium bicarbonate. The two react to form carbonic acid - but carbonic acid is unstable and quickly decomposes into lots and lots of CO2 gas and water.
It's a neat trick - you can make rocket powered toy cars, blow up Lego men, or torment your kids with it.
Just remember: A) Let go of the bottle.
B) Don't do it where someone can tell you off.
C) Don't film until you know you can do it right - you're just letting us all down.......