The metaphorical alarm bells could hardly have rung with greater resonance back on 27 December 1990, the night when the National-Coal-Board-surveyor- turned-millionaire-property-developer took over as chairman of the black and white board.
The once-mighty Magpies had slumped to fourth from bottom of the old Second Division and were in debt to the tune of pounds 5m. "The club is in an horrendous state," Sir John said then. "We have an overdraft limit of pounds 4m and we're losing pounds 700,000 a year in interest charges alone. The haemorrhaging has got to stop."
The following day brought a change for the better. Newcastle beat Bristol Rovers in front of 19,329 at St James', their first win for seven games. Tomorrow night they play host to Barcelona in a Champions' League match beamed live to 151 countries.
"It's an opportune moment," Sir John said of the timing of the announcement that he will stand down from the chair and the board at Newcastle's annual general meeting on 1 December.
"Barcelona was the first place I visited when I set out to build Newcastle United and to start a sporting club. I looked at their team and the 100,000 people in the Nou Camp and thought that some day we'd get there. We're here now. To be playing Barcelona in the Champions' League is the realisation of a dream.
"This club was on the edge of bankruptcy when I first took over. We made a mission statement that we wanted to be one of the top three clubs in the UK and one of the top 10 in Europe. There were many doubters out there. But we're here now.
"I feel I've done everything I set out to achieve. I'm 65 next year. I started work at 16. My father worked 50 years in the pits and he's got a certificate on the wall. I don't want to get that certificate. I want to do other things."
Those are unlikely to include making "good use of his bus pass," as was suggested by Freddie Shepherd, the Tyneside businessman who who will assume the chairmanship with Douglas Hall, Sir John's son, becoming vice-chairman. Hall senior has accepted a life presidency and intends to "travel on the continent in an ambassadorial role."
The need for such duties hardly seemed likely back in December 1990, when Sir John resigned after eight months on the Newcastle board. The share offer championed by his Magpie Group had been an embarrassing failure, attracting just pounds 1.25m worth of applications. Had he not chosen to return a year later, Newcastle would not be taking that much in revenue from one match tomorrow.
They might not have been in any league, let alone the same one as Barcelona.