The article says he bought shares (at $0.001/share, I guess pretty early in the life of the company), not options. Now, maybe a startup that's willing to give you options might also be willing to sell you shares (after all, that's almost what an option is), and might be willing to sell you shares in your self directed Roth.

Sadly, I didn't think to ask the startup I worked for about this. Would have been nice to not pay taxes to diversify.