The Bristol Royal Infirmary inquiry reached a turning point last week. It heard evidence that the quality of surgery may have been the least of the factors which led to the deaths of so many children there between 1984 and 1995. If this evidence has a significant influence on the inquiry's eventual findings, the impact on the NHS will be even more cataclysmic than has been assumed.

A review of 80 casenotes, randomly selected from those of 1,800 children who underwent heart surgery at the hospital, found that in only two cases would better surgery have improved the outcome. The inquiry heard from an expert witness that it would be 'inaccurate' to attribute the difference in Bristol's performance from that of other paediatric cardiac centres to surgery - 'inadequate care' was the decisive factor.

That implies the two surgeons at the centre of the case were not solely - perhaps even mainly - to blame. The casenotes review found a range of factors contributed to the children's inadequate care.

Diagnosis was wrong or incomplete. Treatment before surgery was below standard. The timing of operations - some were delayed - contributed, too. Medical and anaesthetic aftercare was not good enough, nor was the nursing on the intensive care unit. Crowning it all, predictably, comes poor communication.

In short, Bristol Royal Infirmary was an institution under pressure and in crisis. Some may be tempted to conclude from this that the two surgeons struck off by the General Medical Council last year have been scapegoated, and should perhaps be exonerated. But that would be a rush to judgement. Whatever the effects of the shabby environment in which they struggled to function, questions remain about why they persisted with so many operations knowing their mortality rates were so extravagantly higher than anywhere else.

Nevertheless, their performance was part of a broader picture. Inadequate resources and ineffectual management in the face of intense demand for services were clearly crucial weaknesses. What is emerging is not merely a tale of misadventure by a couple of arrogant and unaccountable doctors; it is a description of an institution's failures which will sound alarmingly reminiscent to managers throughout the NHS. For the whole system, not just individuals, was at fault.

The shock waves from the Bristol inquiry will ripple both upwards and outwards. Expect the internal market to be blamed, and ready assurances offered that it is all very different now. But how many managers can honestly say that it is?