I would expect that fiber is much better as far as induced currents from nearby lightning strikes finding its way to equipment. Granted it is still an issue if it takes a direct strike or gets hit by power lines. What I do know is that when the local company used coax cable on the poles we would often have a long outage after a lightning storm. Since they've gone to fiber on the poles we very seldom have an outage.
Most outages are usually cause by limbs downing lines and not due to hits. Fiber has no edge in this regard.
Actually the number one cause of cable system outages is loss of commercial power. Lots of reasons why, but actual plant damage is a distant second in terms of minutes/yr. cable companies have gotten better at maintaining their battery backup systems and monitoring the PSUs, but problems still can happen. Note that a popped breaker on a power supply still counts as loss of power, even though the power company never had an outage. The reason the outage times decreased after the fiber plant went in was because each power supply covered a much smaller service area (think modified hub-and-spoke vs Christmas tree lights archetcture). Easier to find the problem too.
Fiber optic cables are constructed to be much more durable than coax or twisted pair. I've seen poles sheered off at the base by an accident and the top standing up hanging on the fiber. Also, the preferred placement for fiber is underground, which is safer in the long run.