With drones using the (older) LiPol batteries, the drone (aircraft) firmware update will take place, then the drone will reboot. Directly afterwards, if there is a battery firmware flash for the battery, the on-screen firmware prompt will appear...
My Air 3S is spot on when landing too. Don’t touch a thing on RTH, observe the cross hair icon when landing and you will see it adjusting to its original take off coordinates…remarkable precision. Even my Air 2S is pretty spot on. What I’m going...
"Fly Away" coverage, through DJI Care, is the only miracle available, but only if your "friend" had the foresight to purchase it, and use the bound controller for this unfortunate flight!