Per the article they're "as much as 31% higher" than other auto companies.

That should be in the title of the article. "Safety incidents at Tesla plant were 31% higher than industry average in 2015".

Without the 31% higher, you'd expect a 50-50 chance of being above or below the average. 31% higher sounds like its might be statistically significant. You'd need other numbers to be sure - e.g. if there are only 1.53 incidents on average, then Tesla might be the unlucky factory that had 2 incidents instead of 1.

This doesn't answer the question.

Doesn't it? If Tesla is about as dangerous as slaughterhouses and sawmills, and Tesla is more dangerous than other automakers, then it follows that other auto makers are less dangerous than slaughterhouses and sawmills.

The headline says “worse than slaughterhouses and sawmills”, not, “abous as dangerous as”.

So no, it doesn’t answer the question. It could be that slaughterhouses and sawmills are really safe—say 3 on a 1-10 scale—while automakers are 6 and Tesla is 8.

No, I don't think your logic is sound.

The article says Tesla has a worse safety record than slaughterhouses and sawmills.

Accordingly, other automakers may still be more dangerous than slaughterhouses and sawmills, while being less dangerous than Tesla.

If A > B and A > C, you still don't know if B > C.

No, they were in 2015 - in 2017 they are better than the industry average.