I will keep my oppinon as dji are bad news and to stay away because if it. Advertised specs are no where near reality typhoon advertise ranges of about 1.2 km but realistically looking at 1 km. That is reasonable advertising 5km and disconnecting at under 1.5km is just plain false advertising.
Your opinion is in contrast to the experience of many, many users.
There's nothing false about the distances shown in DJI's specs which have been proven to be achievable and Phantoms fly out several kilometres every day of the week.
But they do tend to lose signal when there's a big lump of terrain blocking signal as happened when you turned right.
The error message you saw is a common false alarm and made no difference to any factor of your flight - there were no obstacles in the path of the Phantom.
But without a tonne of money. No way to fight them for It.
If your flight data shows proof of a malfunction, DJI are very good at replacing lost Phantoms.
But when the flight data has no indication of malfunction and shows that the loss was due to the way the Phantom was operated, it's no surprise that they don't come to the party.
Dji don't give a volts so most of the other posts are redundant. They give a percent remaining battery.
But you can see your battery and cell voltages here:
And here:
But DJI tell you in the manual not to fly with a partially discharged battery.
There's a reason for that.
Fact is even at 2 miles per hour it should have still made it back to home and as it disconnected there would be no way to know if it picked up speed after that point. But its safe to say that there wouldn't have been terain in the way as It remains at the hight until it gets to the home point and then desends
No terrain makes no difference when you have your Phantom up nearly 700 feet over hilly terrain where conditions are likely to be gusty.
If you fly your Phantom:
where signal is blocked by terrain
at high altitude where winds are high and underlying terrain
with obstacle avoidance enabled which reduces speed
You stand a good chance of losing it.
Although the Phantom is ready to fly out of the box, the operator might not be.
Down at the park you can get away with some mistakes.
But if you go flying greater distance without regard for altitude, terrain and winds, there can be some painful lessons.
