Q: Could a bad oil change cause a faulty alternator and battery a year later?

A year ago an oil change was done at Firestone. Everything was fine. This week the "battery not charging" light came on and a few days later the car died (at least 3 warning lights popped up). This was the same week the service light came on and I was booked to take the car in the same week anyway. Jaguar service department says the alternator and battery have died, covered under warranty. Under further inspection, they said oil leakage soaked the alternator causing the damage and this is outside of warranty since the oil change was done at Firestone. I'm waiting to hear back from Firestone, but the oil change was so long ago. Is this a viable reason for such a failure? Wondering why it would've taken so long. The difference in mileage between the oil change and the service was 5,000 miles to 12,555 miles.

My car has 12555 miles.
My car has an automatic transmission.