That guy was emulating the feats of the late, great, "Ghost Rider". I say "late" because rumor has it that he died a couple of years ago, and either that's correct, or he's in jail, (or perhaps hospital) because I haven't seen any of his famous (infamous?) youtube videos for awhile, like the one where he rode 43 miles in 15 minutes at speeds up to 170 MPH, in city traffic.
Here in my home state "lane splitting" is legal, but dangerous. I witnessed the aftermath of a lane splitting attempt gone wrong when a car "merged" into a lane-splitting Harley rider on my way to work one morning on Melbourne's infamous "Ring Road". The Harley rider had only zoomed past me a few minutes before the traffic completely stopped, and as traffic crawled past, I saw another motorist putting a blanket over his dead body.
I do lane split myself when in heavy traffic, but I do it very slowly, and keep an eye out for merging cars. I don't think my youtube vid would be very interesting.......... Cheers, Terry.