Would be no issue if he had UAS Remote Pilot Open Category - [UAS-OPEN-A1+A3] certificate; its a pain but worth getting it. Stay Legal, penalties can be severe.
Every hobby I've had has been worth it, drones being the latest. I spent hundreds of thousands on my hobbies, always going over the top, never earned a penny from them but continue to enjoy and cherish every moment with them.
Although I live in the US, I frequently travel across the border (less than a mile away) to BC Canada, I have my SFOC-RPAS for Canada and also passed/have my UAS Remote Pilot Open Category - [UAS-OPEN-A1+A3] certificate should I travel to an EU country. I have personal insurance, AMA (American...
Just go and fly your new drones and enjoy; you'll regret it when/if the MP5 comes out, get value for your money. If you lose or break it, claim it off DJI Care if you have it, else put it down as 'Staff Welfare' expense for a replacement, in your books :D
You may try and look for various calibrations, particularly the gps. When I received my MP4P, it made me go through a gps or magnetic calibration where we need to move the drone in a figure eight/up/down/turn pattern. I think you may need to do that.