MarketWatch are a complete rag of a financial news site. As in this case, most of their headlines are sensationalist link-bait. I guess that makes me a fool for even reading the article.

Look at the chart and it's clear that Tesla's stock price has not 'tanked'; it's trading well within the range it's been in for some time. They are not "defaulting" on their loan, they are re-negotiating it.