Whatever happened, it wasn’t the OBIGG. If that failed during a lighting storm, the bird would have exploded, not glided in.
And the F35 can fly in a storm. There is a very minor risk of the plane exploding — if everything goes wrong and the OBIGG had not been updated — if struck by lightning.
Now, a very remote chance is still a chance one doesn’t take if possible.
But this sounds like some sort of cascade computer failure — possibly caused by lightning. Or (more likely) someone putting in the wrong software module.
I seriously doubt that, but I'm having trouble working out how lightning would affect what must essentially be a medical oxygen concentrator but instead of collecting the oxygen you'd throw it away and collect the nitrogen. I have an oxygen concentrator, and it's too simple a device to have any such sensitivity. N.B. Military aircraft have used nitrogen purge for a long, long time.