Interesting video, but what a worthless article. Clearly the Tesla did not tow the semi uphill in the snow any more than people push stuck cars and trucks up icy hills in the snow. A little extra force applied in the right direction to keep you from just spinning in place and sliding sideways goes a long way.
Listen to the audio, you can hear the truck engine going.
What's interesting is the X moves laterally as if it broke static friction and if it did I have trouble believing it would actually provide enough force to move laterally so easily yet still pull a semi forward.
I wasn't bashing the video, the Tesla clearly helped the semi get up the hill, but definitely under the semi's own power. Much in the same way that somebody on foot can help a car/truck up an icy hill. A little force in the right direction is a big help.
The article though was junk. They more or less go on about the video being a possible staged publicity stunt instead of recognizing it for what it actually is.