iski - clearly you must realize that the vehicle in the Youtube video is not a Mattel Big Wheel (looks like a rice burner to me) but some shallow attempt at a cheap copy.
The Center of Gravity on the Big Wheel was located well below the Axis of Evil which would prevent this type of accident. Big Wheels did suffer from a few other maladies though, the previously mentioned front wheel flat spotting, occasional severe pedal over-rotational torque shearing, the poor ergonomic consideration for BSR's and the unfortunate routing of the exhaust directly into the driver's left nostril. Most of these problems were addressed in later year models. Unfortunately, Mattel's brief experiment with the creation of the CTO division (Custom Trike Operations) and the introduction of the Screaming Turtle powertrain created exhorbitant business losses as well as numerous wrongful skinned knee lawsuits, forcing them to scuttle the entire operation.
Buy early - Yes, this video was a cheap copy of a Big Wheel. Please allow me to explain...... In my misspent youth, my parents could not afford a Big Wheel. We took turns riding cheap plastic crappy copies like those in this video and dreaming of the day when we could have a real Big Wheel. Alas, that day never arrived - we were much too poor for fancy schmancy ride toys. One year I was given a picture of a Big Wheel - closest I ever got to a real one.
I shed a tear while reading your post - oh the shattered dreams of owning a BONA FIDE CTO, with the Screaming Turtle Powertrain, and the exhaust routed into my left nostril. Of course several hundred of my more prosperous friends were killed & and/or maimed for life by these Big Wheels - my Mom cautioned often against riding with the Big Wheel Diaper Angels 1%ers. Many of these miscreants have never fully recovered from a nasty pacifier habit.