Tesla spun bad statistics to make that claim. They're comparing highway driving to all driving, and highway driving is statistically safer. They're also ignoring demographics, as Tesla owners tend to be affluent and older. If you take this into consideration, it actually suggests that it's less safe, however with such a tiny sample size it's too early to draw any conclusions from the data.

https://www.washingtonpost.com/news/monkey-cage/wp/2016/10/0...