Eberhard sued Musk challenging his right to call himself a founder and the case resolved such that Musk gets to keep calling himself a founder. Musk was a major source of funding early on, putting in about 6 million out of a 7 million dollar raise, served as chairman of the board, headed product design for the Roadster, and took over as CEO before they launched the Roadster. Tesla publicly acknowledges him as a founder.

The founder title is one that a company gives to individuals crucial in the early formation of the company. Musk clearly qualifies.

I'm saying all this because I think it's very lame that Musk critics try to say he's not a founder of Tesla. Hate Musk all you want, just use real criticism and not this sophomoric "he's not a Tesla founder" stuff.