This one is a tough listen:
The speaker has English as a second language and Cap'n Kirk pacing. Between listening and reading the [inaccurate] subtitles you can piece together what he is saying.
Long story short, early in the Earth's history Carbonaceous Chondrite asteroids* peppered the surface with simple hydrocarbons than were raised into the atmosphere where UV rays and mineral catalysts produced complex hydrocarbons that rained down and produced conditions similar to Titan today. Over Eons of time tectonic subduction transported these hydrocarbons 20 to 50 miles deep. Biomass is only able to account for 2-6% of the total volume because life feeds on itself and is continuously recycled. Bitumen, shale oil and tar sands all result from the combination of the two processes.
He accepts both biotic and abiotic theory but says the first 20% of biotic and the last 20% of abiotic theory is 'unscientific'. He also uses a lot of food analogies.
*
www.nature.com: Meteoritic evidence for a Ceres-sized water-rich carbonaceous chondrite parent asteroid