I purchased mine with ~14,000 miles. Looking back on the service records all was in order, but I saw that the 1200 mile service was performed at about 2100 miles.
So I called the out of state dealer where the car was originally serviced. The SA there said the 1200 mile service delay was absolutely nothing to be concerned about. I then talked to two more SA's I know here in state, and one Master Tech.. All of which said the exact same. There was never any mention of warranty implications with the late service.
That said, 3400 miles is quite a delay. I'd suggest you consult with dealer personnel that have no interest in selling the car if you know any. Call the dealer where the car had the 1200 mile service, provide the VIN and ask their opinion.