I'm not sure that you understand my standpoint. The bell-curve math model applies to the volume of oil we can pull from a well. What affects how much we can pull from it is the size of the source, and the state of the source (full, half-full, near-empty etc). As we approach the half-full, or less-than-half-full state of the overall world oil sources, maximum possible volume of oil per time inevitably decreases. Something we can do absolutely nothing about, without spending more and more energy towards aquiring energy, like the oil sand in N-America. This will show in production capacity. What this means is that as oil demand continues to increase, our supply continuously decrease, inevitably.
The only question really, is when excatly this half-full state (ore less than half full) of our oil sources will occur. Some say we're already there, while others claim it to be years off still. I say that we don't know exactly, but can only guess. His estimation is as good as anyone's and likely very accurate. The rest of his lecture is all math and doesn't really apply to the world we live in other as an example of how numbers can be mis-used, and how bad things can go if we don't pay attention to what's going on.
