When he got his hand back on his best friend, the display was showing that the device was deactivated for more than 22 millions minutes... That more than 40 years, 43 to be exact in his case. Only thing that could be done was to make emergency calls and that's it!
After reading on the web how to bring back the iPhone to life, there was basically two solutions:
1- Connect to the iTunes computer that is the main controller of the iPhone and the lock should clear itself.
2- Put the iPhone in DFU mode, erase and restore the whole device.
Since his iPhone never was associated with an iTunes computer, the only thing to do was to completely erase it and restore from iCloud. Technically it would have worked, but would have taken a lot of time.
So I figured that the clock of the iPhone was off by 43 years (we are in 2013) bringing the "current" date of the iPhone to year 1970. Then it hit me.
Often, devices and computer have a starting date set to Jan, 1st 1970. Everything is calculated based on that starting date. Since the iPhone had to be disassembled to replace the broken glass display, surely the battery was removed, thus resetting the internal clock to 1970. Since there was no SIM card in his iPhone, it couldn't sync it's clock with the 3G network or even WIFI.
The solution is quite simple. I just put my own SIM card from my iPhone into his, waited a few minutes until the time would show up on his iPhone. And voilà! It was working again. It does not need to connect to the provider's network, only detect a 3G network and that's enough to sync the internal clock.
As I said it took a few minutes until the clock was synced. I even rebooted the iPhone to force things to happen. I eventually pressed the two volume buttons at the same take, taking a picture to trigger an event in the iPhone. By taking a picture, the iPhone does need the time to timestamp the image. At the same time, the clock did synced. I'm not sure if it's a coincidence and the clock would have been synced eventually, but the result was there.
After, I just entered the pass code to enter the iPhone and all was working as expected. I got my SIM card back into my own iPhone and has a very happy friend!
So if your iPhone is deactivated for the next 40 years, this is how you can reactivate it without having to erase and restore.
Hope that it will make you happy too!