Not that I have ever driven one that big, but those trucks where empty. And if that 2nd one was loaded and he hit that berm it may have been a different story.
If you look closely at the boxes on any cat trucks and especially the newer ones like the 798's you will see that they are designed to have the bulk of the weight as low as possible and between the wheels giving them a very low center of gravity and virtually untippable in a slide,thats why in some of the videos you see them perched precariously over ledges with a lot of the truck hanging over empty air.it takes a lot of effort to flip one on their side.
Just look at the shape of the box and how the "V" at the bottom is in between both front and back tires.
They handle better then any pickup truck I have ever drove and I've driven lots of rock trucks,the wabco's were also built like that and also the komatsu's.
Any rock truck driver will confirm this,they are actually a lot of fun in slippery conditions.
The cat trucks do 37 MPH top speed,if they were that uncontrollable they would be cut back but their not for a reason and that what makes them some of the best trucks on the planet.
Now an electric truck is different,most Cat trucks are mechanical drive,big difference in how they handle on slippery surfaces,electric trucks suck on downhill hauls or if the operator has the cruise control on.