That estimate is a little bold: we can reject the hypothesis that the probability is smaller than 1/260 with p-value 0.05 (good confidence), but with your threshold of 1/26 the p-value becomes poor.

Note that due to the lack of selection bias (battery fire was already among the top security concerns before the accident), we don't actually need a very stringent p-value, so we can be fairly confident that the probability is greater than 1/260.

But my point was that even with probability 1/260, it's likely to be much higher than for gas cars, or you wouldn't have to dig up 20-year-old articles about "freak accidents".