Yesterday my son and i were flying our p3s together. We had been doing this all week following each other and getting close  videoing each other while flying.
I was about 1000 metres away at 70 metres up on the other side of a hill out of sight. I lost video for some reason..been flying there before np.
My video locked up on the ipad but i could still see it connected with all the gps. Distance etc.
I flew it back into sight by the map screen on the bottom right hand corner.
He was alongside me and i restarted dji go to try to get the video back.
I got the video back but then his drone started dropping like a stone alongside me from 70 metres up. He still had his video and managed to steer it sway from a lake into the trees. A couple of broken props and cracks was all he got luckily..
I landed mine straight away before mine went down as well or had problems.

Now i thought that if the drone lost signal it was supposed to hover or return to home. But when my app restart affected his it dropped like a stone ?
And my video didnt come back until i restarted the app ?

We worked out from the videos and logs that when I restarted my dji go app to get the picture back it somehow communicated with his drone and did a restart on his as well. We can see the camera spin before it goes into a spiral down to the ground.
So I guess the moral of this story is not to restart your dgi go app when another controller/drone is close.
We have done 2 flights together since then flying u to 1.6 kms away and it's fine flying together.

stevejnz Posted at 2017-1-1 01:20
We worked out from the videos and logs that when I restarted my dji go app to get the picture back it somehow communicated with his drone and did a restart on his as well. We can see the camera spin before it goes into a spiral down to the ground.
So I guess the moral of this story is not to restart your dgi go app when another controller/drone is close.
We have done 2 flights together since then flying u to 1.6 kms away and it's fine flying together.

That is a bit worrying, it should not happen like that.