Im guessing rights to use the names and intellectual property rights were non-existent in the game.
You don't say! Just look at the original Japanese version for Metal Gear 2, it's shamelessly using the likeliness of many Hollywood actors (Sean Connery with an eyepatch was just funny), and a real-life athlete is a character in the plot as a spy.
Well, it was so bad Konami actually went through the hassle of reverse-engineering the MSX ROM directly, even in Japanese versions (you can in fact extract the ROM and play it on regular MSX emulators)
Or Nintendo's Time Twist (and to a lesser degree the Startropic games) take wild creative liberties with real-life characters. They don't make stuff like this anymore.