Introduction
The recent decision in Santos Limited v Fluor Australia Pty Ltd [2025] QSC 184 from the Queensland Supreme Court provides one of the clearest modern judicial statements on construction delay expert analysis. The judgment is particularly significant for delay analysts and experts, as it highlights that methodology and reasoning are scrutinised as closely as conclusions.
For companies that specialise in delay analysis, this case sends a strong message:
Decision makers are far more interested in clear reasoning and real evidence than in complicated models or impressive-looking software outputs.
Two Experts, Two Very Different Stories
In this case, the claimant was Santos Limited and the defendant was Fluor Australia.
Both sides hired delay experts who agreed on an initial methodology; as-planned vs as-built windows analysis. However, their conclusions were contrasting due to one expert’s decision to apply ‘but-for’ scenarios to their analysis.
The claimant’s expert carried out an as-planned vs as-built windows analysis. They looked at what was originally planned and compared it with what actually happened on site, breaking the project into time periods and showing how critical path delays built up over time.
The defendant’s expert tried to argue that if certain delays had not happened, the project would still have finished late anyway, because other tasks were nearly critical.
The referees preferred the former approach, as did the Court. The referees found the evidence of the claimant’s expert to be “consistent with the objective factual circumstances and, indeed, was supported by a prodigiously detailed analysis of background facts and documents. It was unshaken in cross-examination”.
Judge Freeburn commented on the near critical path analysis undertaken by the defendant’s expert. The judge concluded the evidence did not demonstrate these near critical delays ever became critical. He asserted that the, “process of identifying the critical path, that is what is controlling the progress, is fundamental to the agreed process”.
Why Near Critical Paths Are Not Your Friend
The defendant expert’s evidence relied on a ‘but-for’ scenario, which relies on the following proposition:
‘If this delay had not happened, something else would have caused delay anyway.’
The problem is that construction projects do not behave like that. When one delay is removed, the whole sequence of work can change. A different activity may become critical, or work might be done in a different order. Delay experts must rely on the facts only and not hypothesise about what could have happened.
The Court accepted that you cannot safely assume the project would have been late anyway without showing what would actually have happened. Delay analysis has to reflect how projects behave in real life, not how they might behave in theory.
Why looking at what actually happened is important
The claimant’s expert focused on actual progress. They identified:
- What the planned intent of the parties was.
- What actually happened contemporaneously.
- How specific problems caused the project to slow down and identified critical delay to completion.
By working through the project periodically, they were able to identify the critical path and evidence delay against as-built site records. This made their explanation easy to follow and hard to argue with.
The Court said this was a sensible and reliable way to show cause and effect while acknowledging their analysis “is actually derived from a detailed analysis of the facts and documents of the project”.
The lesson is simple: Methods based on real progress are easier to trust than methods based on imagined alternatives or reliance on over complicated software modelling.
What About Industry Guidance?
The defendant complained that the referees preferred an approach that followed guidance from the Society of Construction Law Delay and Disruption Protocol. They argued that the Protocol was not part of the contract, so it should not be relied upon.
The Court agreed that the Protocol is not legally binding. However, it also said that it is helpful guidance on how delay analysis should be done properly. While Judge Freeburn noted “…the SCL Protocol is not a straitjacket…”, following it shows that an expert understands accepted industry practice.
Freeburn added that “…the referees were uncomfortable with the logic of [the defendant’s expert’s] departure from the agreed SCL Protocol methodology”. This case provides a gentle reminder to all of us that whilst the Protocol is not law, it is still a useful benchmark for professional behaviour.
Evidence Matters More Than Theory
The referees decided that one party had clearly shown how breaches caused delay and the other party had failed to show any real alternative explanation. The Court agreed with this.
This highlights an important point:
Delay analysis is not about debating possibilities. It is about proving what happened using facts and records. If an expert cannot connect delay events to real site activity, their opinion is unlikely to be trusted or relied upon by decision makers.
The Importance of Record Keeping
An important lesson from the case is the critical role of good record keeping in construction projects. Delay analysis is only as strong as the evidence that supports it. Contemporaneous records such as programmes, progress reports, site diaries, photographs, and meeting minutes allow an expert to show what actually happened and when.
Without reliable records, any delay analysis risks becoming speculative and assumption-based, which courts and tribunals are unlikely to accept. Proper record keeping therefore underpins the ability to demonstrate cause and effect. It strengthens the credibility of expert evidence, and significantly improves a party’s prospects of success in any delay-related dispute.
What This Means for Delay Experts
Santos Limited v Fluor Australia Pty Ltd [2025] QSC 184 shows that delay analysis is not just a technical task. It is about judgment and communication.
A good delay expert should:
- Use a clear method that others can understand.
- Show how one delay event led to another, relying on contemporaneous as-built records to support the evidenced delays.
- Follow recognised guidance sensibly and avoid speculation and assumptions.
In short, the expert needs both technical skill and practical construction understanding.
What This Means for Clients and Lawyers / Instructing Solicitors
For those choosing an expert, the message is clear:
Pick someone who can explain the story of the project, not just produce complex diagrams or rely solely on software modelling. An expert who relies on theory or assumptions without real evidence risks having their work rejected.
The most persuasive expert is the one who can describe the project and delay in a way that is easy to understand and does not over complicate it. Ultimately, many decision makers are not from a delay background. Making the analysis and conclusions easy to follow while simultaneously relying on actual records will be preferred.
Final Thought
Santos v Fluor reminds us that delay analysis is not about clever models or colourful programmes. It is about explaining why a delay happened in a way that makes sense.
Good experts don’t just show where the critical path is, they show where it is and why it moved, using the facts.
That is what the Court trusted — and that is the lesson for everyone involved in delay analysis.
If you are dealing with delays or claims in your project, getting the right help early can really make a difference. Get in touch with Jamie or one of the team and we can support you with all aspects of delay analysis and claims management, from live projects through to disputes.
For more help with this or any related issues, get in touch today.
