Well lets see what the author of this mod, Patrick Wildenborg, has to say about all of this.
All the contents of this mod was already available on the original disks. Therefor the scriptcode, the models, the animations and the dialogs by the original voice-actors were all created by RockStar. The only thing I had to do to enable the mini-games was toggling a single bit in the main.scm file. (Of course it was not easy to find the correct bit). The Nude models that are used as a bonus in the Quick action version of the mod, were also already present on the original disk.
But all this material is completely inaccesible in an unmodded version of the game. It can therefor not be considered a cheat, easter-egg or hidden feature. But is most probably just leftover material from a gameplay idea that didn't make the final release. I would really like to stress that this material is only accessible after willfully applying the hot coffee mod (or something similar) to the game.
- Patrick Wildenborg
Now its time for Rockstar Games themselves to comment on the issue:
"So far we have learned that the 'hot coffee' modification is the work of a determined group of hackers who have gone to significant trouble to alter scenes in the official version of the game. In violation of the software user agreement, hackers created the 'hot coffee' modification by combining, reconstituting, and altering the game's source code......
....since the 'hot coffee' scenes cannot be created without intentional and significant technical modifications to the game's source code, we are currently investigating ways that we can increase the security protection of the source code and prevent the game from being altered by the 'hot coffee' modification.