Since then, they have solved the bug, and there is even a ticket with regards to it on Rockstar’s support site.
Then, Rockstar has made an official statement, saying that it was a bug and that it was not them making any changes to the DRM of GTA 5. However, once that happened, the Steam version of Grand Theft Auto 5 just could not be played by users in offline mode. We have all seen earlier this week how Rockstar Games Launcher made its appearance.