When the Fifth Doctor visited the Director-General, the DG did not recognise that the Doctor looked remarkably similar to the traitor character from the programme. He merely thought the Doctor looked familiar, and supposed they had played rugby together once. He even told his secretary, Anita Scammell, that the Doctor was an old friend.
The Doctor was able to convince the DG to help him end the programme by reminding him that he had vouched for the Doctor to his secretary, who believed the Doctor was the evil traitor from the programme. The DG told the Doctor that the only way to end transmission of the programme would be "World War Three", that is, if ratings fell to zero, the computer would assume a nuclear holocaust and shut down the programme. He was unable to tell the Doctor where the ratings processor was.
After the Doctor left the DG, Anita led an angry mob to his office; the DG was saved by the timely transmission of the next episode of Surrender, Earthlings! Like the rest of the humans, the DG suffered withdrawal symptoms after the Doctor and Nyssa ended the programme. (PROSE: Not So Much a Programme, More a Way of Life)