Whoever was reporting on it most likely called Mecum's bidder line before the auction to ask what they thought thought the car would sell for.
I'll bet their reply would've been $6.5M, only to pump up the excitement on such a rare piece of machinery. Mecum auction's are great, but they try to squeeze every nickel out of a car they can get. I don't blame them though. It's what they do.
When Mecum was in Schaumburg, IL a few years ago, I called them about a cream 70 300 that was going on the block, and had been sitting in a dealership's window for years, which was being offered for the first time for sale to the public. Extremely clean and all original. They told me the seller wouldn't take less than $12,500 for the car, so I opted to not buy a bidders pass for $150 because the market was not there at the time for those kind of prices.
The next week, I went to Mecum as a drooler, and saw the 300 in the back parking lot of the convention center with a "Sold" sign on it. It had been sold for $4,700, IIRC. Son of a B!
I would've gone for it at that price had I known, but somebody else walked away with a sweet deal on that car.