I think your memories playing tricks on you. The keep ball phase of that game was only the last 5 minutes at most. According to Tommy Hutchison, both sets of players had received messages from the sidelines and knew the Sunderland result before it was flashed on the score board.
Gordon Milne was on CWR last week and confirmed the decision to delay the game was totally down to the police and their concerns that so many fans were still outside the ground. Jimmy Hill’s influence on that game really has been over exaggerated.
With regard to Hill swigging Champagne with Alan Dicks (who was his former assistant as mentioned above) after the game, this may well have happened but again perhaps memories playing tricks as there is a famous picture of Gordon Milne filling Alan Dicks Champagne glass in celebration after the game.
The fact the teams stopped playing, albeit for only a few minutes at the end, wasn’t great and shouldn’t have happened, but the fact Hill still gets the blame even though he was exonerated by an FA enquiry seems unfair as does the fact that Bristol seem to have got off Scot free.