I think OP is saying he drove 1000 miles, even though it already needed an oil change before he started.

Saying that, you're right, why on earth did they let the car go out of the lot, knowing that?

I know nothing about the operation of car rental companies, but I'm guessing they change them less often than every 3000 miles, which is typically when the lights come on, I think. They probably just forgot to reset the light. I'd expect them to keep track of the mileage and ignore the oil change indicators. Pure speculation here, though.

Newer cars no longer need 3000 mile oil changes. Most cars with synthetic need an oil change every 7500 miles, BMW's for example only need an oil change every 15k miles.

3k would be a waste, the oil is practically still new at that point.

In most parts of the world 10k+ intervals have been standard for a long time.

My (US) 2012 Mazda is 5k for Schedule A and 6.5k for Schedule B. Maybe high end cars have higher intervals?

Strange! Compare to: http://www.mazda.co.uk/buying-owning/maintaining/service-sch...

My Subaru Impreza has a 7.5k mile oil change schedule, and i wouldn't call it a high end car.

Miles or km? 10k miles is a more recent change since about 2007 - 2008 or so with better synthetic oils.