> You can just leave batteries in and it knows when to stop charging.

This is true of all modern lithium ion consumer hardware, because if you don't get this part right, the battery explodes and burns down your house the first time.

One of my co workers decided to charge his drone at the office and found this out . Or more accurately the whole office did

The DJI batteries and charger are very clever too. The batteries auto discharge to a safe level after 2 weeks on the shelf

Is there now a section of the employee policies that forbids charging drones in the office?

The manuals have always told people to charge outside, for this reason.

Not when the charger says "for home and office use only"

There's probably some weird clause in the usage guidelines saying you need to have the charger attended all times it is plugged in or something like that.