Water pump leaking

I have a 2003 Jaguar S type with a 6 cyl engine. It has 31,000 miles. I took it to a local service station for an oil change and a week later the light came on saying low engine coolant. I returned to the service station and they told me that I have a leak in the water pump. Could they possible have caused this and would they not have been able to tell if it had a leak in when changing the oil. It had no problems before taking it in and should not be leaking after 31,000 miles.