Price and inspection
If the price is right and car is in great shape, it's no different than buying any other used car. You might want to take the car to an independent Lotus Dealership for an inspection if you really want piece of mind. Other than that, find the inservice date for the warranty and you should be good. If the car was truly beaten, there will be signs of wear and tear that should come out on any inspection.
You can also request them to do an ECU dump and then judge for yourself.
If the rear tires are still at 85 % and the clutch isn't slipping, I would doubt it had too much abuse. It doesn't take long to run down high ends tires like those that come on a Lotus if you are driving like an idiot.