Fans generally don't require an earth, they should always be provided with one though - just made safe in the fan. That'll be why he's done it. So long as it's connected at the other end it isn't a disaster.
The fan has switched line and neutral swapped as per the JB in the loft. You can swap them and see if it works but the fan is likely blown.
The fan has switched line and neutral swapped as per the JB in the loft. You can swap them and see if it works but the fan is likely blown.