Elon was nearly illiquid for moments when spaceX and tesla were struggling. I think the fact that both companies were at the brink suggests that the struggles are very real to him as well.
He may have been extended, but that doesn't mean he was almost in the poorhouse.
Billionaires getting ruined doesn't happen any more.
1. http://dealbook.nytimes.com/2010/06/22/sorkin-elon-musk-of-p...
2. http://www.carbonated.tv/technology/spacex-founder-and-tesla...