More than two months after the launch of ill-fated Note7,The Swingin’ Stewardesses we still don't know what caused the batteries in some of the devices to overheat and, in some cases, explode.

A new report by Instrumental, a company that helps tech companies fix manufacturing issues, suggests that the reason behind the Note7 issues was Samsung pushing the boundaries of the design a little too far.

More precisely, Instrumental — after tearing down and examining a Note7 — found that the Note7's battery sits too tightly within the device, so that pressure from normal operation (such as sitting down while having the phone in your back pocket) can cause layers of lithium cobalt oxide and graphite to touch. This should never happen, as it can cause overheating and an explosion.

Interestingly, Instrumental states that even if the batteries didn't start to explode, they would start swelling "a few years down the road." For a detailed explanation, go here.

This isn't Samsung's first smartphone. So why did the company design it like this? Instrumental speculates that the company's engineers were simply cutting it too close with safety margins, and that there wasn't enough time to test the new design.

"It’s possible that Samsung’s innovative battery manufacturing process was changing throughout development, and that the newest versions of the batteries weren’t tested with the same rigor as the first samples," Instrumental wrote in a blog post.

As far as salvaging the Note7, Samsung could've fixed the issue by using a smaller battery, but that would've reduced the phone's battery capacity too much, according to the report.

Samsung permanently discontinued the Note7 in October. A month later, the company published an apology to users in several major U.S. newspapers and vowed to fully investigate the reasons behind the Note7's debacle and make them public, but we're still waiting for that explanation.