In a damning report, the city council's scrutiny committee investigating the controversy says planning constraints regarding access, sight lines, height and heritage issues should have been spelt out before the project went out to tender.
The inquiry, which took more than 50 hours of evidence from 21 witnesses, found that only one of the four shortlisted schemes could ever have gone ahead and partners should have re-evaluated the project at that stage.
The report says the consortium and steering group should have resolved planning and heritage issues relating to the design of the bridge and residential towers by the end of the proof of concept stage. This failure was a "fundamental flaw", it contends.
The report does not mention names but blames the lack of public sector leadership for the collapse. The appointment of a lead agency was essential to drive the project forward and to avoid a call-in that would have destroyed the possibility of securing Objective 1 funding, it found.
This was one of the reasons the public sector gave for withdrawing support for the scheme. The scrutiny panel accepted this justification but said it should have been dealt with earlier.
However, the panel disagreed with the public sector's assessment that the scheme was "not what was originally bought" and that it had lost confidence in the consortium's ability to deliver. It argued that these judgements were subjective and open to interpretation.
The report speculates that the public sector may have had other reasons.
But the panel says it was not given a copy of the minutes of the meeting when the decision to withdraw support was made.
Chairman Paul Brant said the panel does not want to see the recommendations sitting in a drawer gathering dust. "We will be revisiting this in six months or so to see what progress has been made in implementing our work," he added.