In the beginning of this video it looks like the player is actually pizzicatoing with the left-hand and playing regular notes on a different string, is that what is happening? Is that even a thing?
is that what is happening?
It certainly is.
Is that even a thing?
It wasn't before Paganini came along. He was the best violinist in the world in his day. Initially his problem was that extant composition for the violin wasn't sufficiently difficult to highlight his superiority. His solution was to compose music that, to begin with, only he could play.
Paganini went on to become the early 19th century equivalent of a modern rock star, going on tour where he was payed fantastic sums of money to perform and with modern style female groupies.
Today, however, when there are more violinists alive than have died through all the ages, pretty much all the top soloists are expected to and can play his compositions. So, yes, simultaneous left hand pizz and arco are a thing at elite levels.