Ignorance is obviously not bliss !
Next time you walk around an aeroplane you will see that there is a scoop underneath the wing near to the tip (naca duct)
Those of us who remember Tridents, 1-11'S
Etc would be familiar with seeing fuel streaming out of wing tips exactly the same as in this photo.
The duct is used to provide a positive pressure on top of the fuel tank (to prevent cavitation) and is protected by a float valve to prevent fuel spilling out, when the valve sticks open and the tanks are exceedingly full, it is normal to see fuel spilling out of the vent.
Ihave seen a/c take off with fuel streaming out of both wings !
The vent pipes are situated at the very top of the tank, and a change of attitude or small burn off either reseats the float valve or reduces the level below the stack pipe.
100 squids says that was the case here !
