He has a point.

In a discussion on CNBC Monday morning, Robert Murray, CEO of coal-mining company Murray Energy Corp, took a shot at electric car manufacturer Tesla over the taking taxpayer subsidies and failing to turn a profit. Following the attack, Elon Musk took to Twitter to refute the claims and challenge Murray’s beliefs head-on.

In the CNBC discussion (viewable here), Murray said “Tesla is a fraud. [Musk has] gotten $2 billion from the taxpayer, has not made a penny yet in cash flow, here again it’s subsidies.” The Trump-supporting CEO continued on to say that Democratic presidential nominee Hillary Clinton intends on giving subsidies to “Elon Musk, Warren Buffett,” and her other rich “friends” and that it would have “nothing to do with supporting the environment.”

Following the live footage, Musk tweeted out a link to the interview and another one stating, “Real fraud going on is denial of climate science. As for ‘subsidies,’ Tesla gets pennies on dollar vs coal. How about we both go to zero?”

I would note that it is in Big Coal’s best interests to support electric cars like Tesla. After all, a lot of electricity is produced by coal while zero cars with an internal combustion engine are. Notice that Musk doesn’t actually refute the point.