Inspire 1 Raw fell from the sky -- what the hell happened?

I did recover the drone after three days in the ocean -- thankfully, it was only in two meters of water at the top of the reef (which is why we didn't find it the first time -- we were looking deeper). So I was able to recover the video off the microSD card, including a video earlier in the doomed flight (from 40s - 88- into the flight). The drone wasn't recording at the time of the sudden failure though. I also couldn't recover anything off the SSD -- not sure if it's because there's corrosion on the connections, or internal damage, or what.

For what it's worth, the battery was firmly wedged in place when I found the drone. More amazingly, it was still intact -- I figured it would've just as likely exploded/burst into flame after being submerged in 2 meters of water, but maybe the pressure wasn't enough to penetrate the cell and there were no punctures.

Also, at the time of the disconnect, the drone was climbing and flying forward at somewhere between 20-40km/h. Aside from the force of gravity, the inertia would've been operating to keep the battery in place. It seems rather implausible to me that it would suddenly "pop out" at that point. Also, shouldn't there be some sign of these intermittent/poor contacts in the log?

Regarding DJI.. nothing conclusive yet. The language barrier makes interpreting the emails I've received from them a bit iffy, but as best as I can determine, they don't have a policy against refusing warranty claims for flights with 3rd-party apps per se -- they just categorically refuse to use the Autopilot telemetry log. Or at least the tech support person I've been communicating with refuses to. He's promised to put me in touch with another department though, so I'm hoping that'll be more productive.