May have, or the leak may have attracted the lightening.
Lightening seems to be attracted to dead or dying plants.
Where I live there is number of dead trees that survived hurricanes Rita and Ike but over time they died.
Those trees are lightening magnets when they were still alive but on the way to dying.
Same thing may have happened.
Dying trees are lightning magnets because they have reached their full life span and are the tallest trees in the area. Your logic is sadly missing. Are you suggesting that because oil develops from dead vegetation that there is some relationship?
I can easily see corrosion from a break in the fusion bond epoxy coating combined with insufficient cathodic protection putting iron into the soil to increase the chances of the path of current for lightning.
That said, it still sounds very unlikely.
I would expect a lightning strike into a pool of crude to result in quite a fire. Most crudes cannot be lite by a match but a lightning strike is going to be vaporizing heat and would be burning.