Assume that when the driver left, the photographer had turned his watch to a random time of 2:00 PM.
Let the total travel time of the driver be 2t, as he drove with the same speed on his forward and backward journey.
On the driver's return, the photographer's watch read (12 + 5/60 + 2t). From this, he could find out the value of t. The driver's journey from the time he quit the forest officer's home was T+t ( T being the time the driver noted while setting back for the jungle from the forest officer.) Since both the quantities are known the correct time could be determined.