Can lightning strike into the phone line damage electronics in the house through the ADSL modem?
There are many 'entry points' to your house for electrical disturbances, once lightning has struck close by, and the most important of these is the mains. A nearby strike will lift the ground potential, and induce a voltage into any wiring.
My anecdote is that I live in a row of houses. A house 4 doors up was struck by lightning. They needed to be totally rewired and replastered. Cables had blown out of their walls. Their neighbour's wiring survived, but they lost every item of electrical equipment, including simple motor-only things like fans. Their neighbour's motor-based equipment survived, but they lost all electronics. I lost only my ADSL modem, perhaps as it was connected to mains and the phone line, but all my other electronics survived.