Professional Details

Dr Stephen Castell, Chartered IT Professional and Member of the Expert Witness Institute, is Chairman of CASTELL Consulting. He is an internationally acknowledged independent computer expert who has been involved in a wide range of computer litigation over many years.

After receiving a First Class Honours Degree in Mathematics, Physics and Psychology from London University, Dr Castell carried out research in Mathematics (Computer Science and Fluid Mechanics) at Nottingham University, where he was awarded an MSc (1969) and PhD (1972). He was a senior applied mathematician and research manager in industry before joining Touche Ross & Co as a Management Consultant, working on a variety of commercial computer systems projects, particularly in the banking and finance sectors. Prior to forming his own IT management and financial consultancy, CASTELL Consulting, in 1978, he was for three years Group Management Services Manager for Bremar Holdings Limited, international merchant bankers, involved also in corporate finance and venture capital.

CASTELL Consulting, currently in its thirty-fouth year, provides independent professional consultancy and expert services in computer systems, software, management, strategy, and contract disputes, to a wide variety of international clients and companies. As an Expert Witness in computer litigation Dr Castell has acted in many cases including the largest and longest computer action to have come to trial in the English High Court. He is the author of the best-selling Computer Bluff (1983), and of The APPEAL Report (1990) on the admissibility of computer evidence in court and the 'legal reliability' of information systems and technologies (with the CCTA).

Disputes over failed software construction projects raise interlinked technical and legal issues which are complex, costly, and time-consuming to unravel - whatever the financial size of the claims and counterclaims, the facts and circumstances of the contract between the parties, or the conduct of the software development. CASTELL Consulting has been involved as Expert in a wide variety of such disputes. The practice is regularly instructed (in the UK, Europe, the Arabian Gulf, Australasia, and the USA) in substantial legal actions over contracts which are terminated, with the software rejected amidst allegations of incomplete or inadequate delivery, software errors, faulty design, deficient systems performance, shifting user specifications, poor project management, delays and cost over-runs. This Expert work is routinely for Claimants and Defendants; software customers and suppliers; in the High Court, or in Arbitration, Mediation or other forms of ADR. Dr Castell is also himself a (CEDR-trained) Mediator and (ICC) Arbitrator.

One of the most important issues on which a party's Expert, or, say, a court-appointed Single Joint Expert, is asked to give an expert opinion in software development or implementation cases is: what was the quality of the delivered software and was it fit for purpose ? To answer this, and other equally crucial technical questions posed in software contract cases, CASTELL Consulting has over the years developed a range of rigorous analytical techniques, Forensic Systems Analysis ©®™, for assessing failed, stalled, delayed or generally troublesome software development projects. These techniques, founded on sound software engineering principles, are objective and impartial, favouring neither customer nor supplier, software user nor software developer. This objectively justifiable and properly unbiased approach is particularly important where software projects involve a mixture of 'customised' software packages and 'bespoke' software construction. The methodology also brings sound principles of project management to the conduct of the litigation, arbitration or other ADR process itself, and Dr Castell is now often involved in assisting lawyers handling such matters on behalf of their clients with the introduction of rigorous, timely and cost-effective 'dispute project management' techniques, checks and deliverables.

Dr Stephen Castell CITP: Significant Criminal Case Involvement
Crown Court – Criminal Prosecution for Theft.
An Expert Report was produced and served on behalf of the Defendant who, when employed by a major retail store chain, allegedly made fraudulent credit card refund transactions to his own credit card using the store’s electronic till system. Expert technical investigations revealed that the design of the system was such that it was ‘neutral’ as to whose credit card could be used for such refunds and no system security checks were made nor audit trail produced. It was therefore not possible to prove beyond any reasonable doubt that the Defendant had made such erroneous refunds deliberately, and with criminal intent, rather than by innocent mistake, or even due to a sporadic system malfunction. The findings of this expert investigation were clearly reported by Dr Castell to the court and (most unusually) were fully accepted by the Prosecution without any need for cross-examination, assisting in achieving a Not Guilty verdict from the Jury.
This case reveals some potentially serious security and integrity issues concerning credit card refund transactions in the retail sector. The store chain in question utilised, without any customisation, a leading 3rd-party credit cardswipe and pinpad authorisation package widely employed in electronic till systems across the whole retail industry.

Dr Stephen Castell CITP: Significant US Case Involvement
Digital TV/Databroadcasting - US Patent Actions.
Dr Castell has been appointed in re defending patent infringement actions (i) as consulting expert on behalf of DirecTV concerning US Patent No. 5,404,505; and (ii) as testifying expert on behalf of EchoStar (and Hughes, DirecTV, and Thomson) concerning US Patent No. 6,076,094. Expert investigations, evidentiary documents and insightful analyses have been provided on prior art and inventive step, as regards possible invalidity of the respective patents, from the perspective of inter alia Dr Castell’s unique professional and business involvement in the launch and development of the international databroadcasting industry, and associated innovative data broadcast systems and design techniques (for example, in his high-profile role as Business Development Consultant to the British Broadcasting Corporation for BBC Datacast, 1986-1992).