So i spent a little time reviewing the log. The log indicates that the battery % is good enough, but if you look closer the overall battery VOLTAGE drops and this is why.
- At 39:19.1 in the flight a warning pops saying "Tips__Low Power. Returning to Home Point". Battery level shows 54%, but the log shows 40% voltage.
- At 41:44.4 another warning pops of "WarningPropulsion Output Limited. Aircraft motility has been lowered." Battery % is 38%, but your volts are only at 6% left.
- And then at 41:59.5, another warning shows again of "WarningPropulsion Output Limited. Aircraft motility has been lowered.". Battery is at 36%, but volts only show 2% left.
- At 42:36.5, the altitude starts to drop significantly. This is where you (IMO) started to fall. The battery showed 32% but voltage showed only 2%.
I believe that something in your aircraft, or software failed and resulted in your crash. The battery % and voltage readings are WAY off. And, despite the fact that the aircraft detected a low power state and attempted to return home, auto landing should have probably kicked in an landed, but it did not (did you have this feature disabled in DJI Go?). Instead, it appears as though the voltage ran so low that it stopped powering your engines. I believe, based on the video, there is evidence of the engines slowing, it falling, them trying to go again and then continued decrease in altitude. The landing doesn't look like a "my prop broke and I'm falling", its a slower/controlled descent .. like power was running somewhat, but not optimal and too late to fight gravity.
I personally think that one of the latest DJI firmware updates to batteries (to handle cold environments) is causing issues. I believe that under the right circumstances, the battery temp increases and as a result, the voltage drops and it stops producing the required force to keep the bird in flight.
I'd file a support ticket with DJI and try and get them to repair under warranty. I don't see anything you did wrong. You didn't even cancel the RTH .. it was making its way back.