He is obviously not an expert in Li-ion chemistry, but in the battery industry, which has more business than technical aspects.
But one should also question Tesla communications. For example, Elon said that even if the electricity comes from coal, Model S is still greener than a normal ICE. Just like oil, coal has to be extracted (much harder) and transported, but not refined. Let's put the 20% loss during refining into the 7% electric grid loss + 10-15% EV charging loss (let's forget about vampire loads etc.).
More than 2 lbs of CO2 are produced for 1 kWh from coal. This moves your Model S for about 3 miles. This means about 0.66 lbs / mile.
1 gallon of gasoline is about 6.07 lb. Burning is 2C8H18 + 25O2 ~> 16CO2 + 18H2O, that means 228 lb of gasoline produce 704 lb of CO2 (C is 12, H is 1, O is 16). Or a gallon of gasoline produces 18.74 lb of CO2. So to get to 0.66 lb / mile means around 28.4 mpg, which is average, much worse than my Prius.
Given that the car consumes much more energy to be produced and that after 10 years you may get a new battery, who knows, maybe is not greener. We all want to get to 100% renewables, but this will not be here in less than 50 years. Let's stay optimistic but pay attention to scales. For the time being, coal is pushed aside by a surprise contender: natural gas from fracking. Is it better? I don't know.
In China, where 1 new coal power plant was built every week for almost a decade, is it better to go EV full blast, or small cars like Volkswagen Lupo that may go above 60 mpg ?