Here's a question: Could Starpath's Supercharger have played a part in it? I mean, it was released somewhere about the year before the toy fair in question.
I mean, sure, it used cassette tapes, and it really only expanded the RAM to 6k, but a rig like that could have made it possible...
Heck, it's all academic anyway, and it could very well have been that GGC was blowing smoke, but I'm up for a game of "Speculation!" if anyone else is willing to play.