Expert witness: role, rules and significance

Who is an expert witness?

An expert witness is a person with professional knowledge in a particular field who is called to testify in court on their professional opinion. Unlike an ordinary witness, who testifies only about facts they saw themselves, an expert witness may, and is required to, express an opinion on technical questions. In claims for construction defects, medical negligence and road accidents, the expert opinion is often the main evidence for the decision.

Expert witnesses are used in fields such as medicine, engineering, construction, accounting, handwriting comparison, real estate appraisal and many more.

How does the court examine the expert’s qualifications?

An Israeli court does not blindly accept every expert opinion. Before accepting the expert’s opinion, the court carefully examines their qualifications and the extent of their authority in the field. Among other things, it checks:

• Education and formal authority in the field: academic degree, certificates, professional license
• Practical experience: years of actual work in the field they testify about
• Scientific or professional activity: publications, research and lectures in the field
• Previous experience as a witness: whether they testified in the past, and whether their opinions were accepted
• No conflict of interest: they have no financial or personal connection to one of the parties that could harm their neutrality
• The field of expertise: the expertise must be in the very question in dispute, and not in a related field

Procedure: notice of an expert opinion and filing rules

In Israel, filing an expert opinion is subject to the rules in Chapter 14 of the Civil Procedure Regulations, 5779-2018, and to section 20 of the Evidence Ordinance [New Version], 5731-1971 (פקודת הראיות [נוסח חדש], התשל״א-1971). Anyone who wants to rely on an expert should note the following points:

• Filing deadline: a party that wants to prove a medical matter attaches the opinion to its pleading (regulation 87); in other matters it is filed no later than 90 days before the date set for hearing evidence, and a counter-opinion up to 30 days before that date, unless the court ordered otherwise (regulation 87(e)–(f)). A party that did not attach a medical opinion and did not receive an exemption will, as a rule, not be able to prove the medical matter (regulation 93(a))
• A detailed written opinion: the opinion must include the expert’s name, education and experience, field of expertise, the tests and documents they relied on, and their reasoned conclusions. It is drawn up according to the form in the First Schedule to the Evidence Ordinance, or as similar to it as possible (section 24(a)), and a list of the sources it relies on is attached to it (regulation 87(g)). It is treated as testimony under oath for the purposes of the offense of perjury, and it includes a declaration by its author that they are aware of this provision (section 25)
• Clarification questions and cross-examination: the other party may cross-examine the expert, and the party that filed the opinion ensures that the expert appears (regulation 87(h)). Written clarification questions are sent, with the court’s permission, to an expert appointed by the court (regulation 91(c))
• Counter-opinion: the other party can file an opinion by an expert on its behalf, to respond to the findings of the first expert
• Court-appointed expert: the court may at any time appoint an expert of its own (regulation 88), and sometimes it directs the parties’ experts to meet and narrow the professional disputes

Timetable for filing and examination

1. A medical matter: the opinion is attached to the pleading; a plaintiff who disputes a medical opinion attached to the statement of defense files a counter-opinion within 60 days of its service (regulation 87(a), (c)).
2. Any other matter: up to 90 days before the date for hearing evidence, and a counter-opinion up to 30 days before it (regulation 87(e)–(f)).
3. Appointment by the court: the opinion is filed within 60 days from the day its author learned of the appointment (regulation 91(a)).
4. Clarification questions: an application for permission to send them within 14 days of receiving the opinion; the answers within 30 days of the decision (regulation 91(c)).
5. Examining the person appointed by the court: you ask for a summons by the concluding pre-trial hearing; if the opinion was given after it, at least 45 days before the hearing of evidence or within 7 days of receiving it, whichever is later (regulation 91(d)).

For the deadlines in regulation 87 and the deadline in regulation 91(a), the court may order otherwise. An agreed appointment is already considered at the preliminary meeting between the parties (regulation 35(a)(3)).

A court-appointed expert versus a party’s expert

In Israel there are two types of experts, which differ substantially from each other:

• A court-appointed expert (a neutral expert): the court appoints an expert who is not connected to either party. The expert files their opinion directly with the court; the court sets the expert’s pay, may impose it on the parties or on one of them, and at the end of the trial decides who will bear it (regulation 92). Their opinion carries great weight in the decision.
• An expert on behalf of a party: each party may hire its own expert to support its position. Such an expert must also give a truthful and professional opinion, but the court is aware that they were hired by one party and examines their opinion accordingly

Rights and duties of an expert witness

An expert witness has rights, but also serious legal duties:

• A right to payment for their time, work and expenses. It is usual to settle the payment in advance, in a written agreement
• A duty to give a true and faithful opinion according to their professional knowledge, even when it is inconvenient for the person who hired them
• A duty to be independent and without conflicts of interest with the parties. Payment that depends on the outcome of the trial, or a personal or financial connection to one of the parties, may lead to the opinion being disqualified
• A duty to stay within their field of expertise: an expert may not express an opinion on matters outside their knowledge
• A duty to give a detailed and understandable opinion: an opinion that the court cannot understand and examine will be of no use

How much weight does the opinion carry, and when does the judge reject it?

An expert witness’s opinion can be a decisive factor in deciding the claim, but the judge is not bound by it. In other words: an expert opinion does not bind the judge. The court has discretion to accept or reject the opinion, even when it is the only opinion in the file. However, in practice:

• If the experts of both parties reached similar conclusions, the court will usually adopt them
• The court examines each expert’s credibility: whether their opinion is reasoned and consistent, and whether they are neutral
• When the opinions contradict each other, the court may prefer one of them, or appoint an expert of its own
• Courts have more than once rejected an expert opinion when it contradicted other evidence in the file or was not properly reasoned

How to prepare an expert opinion that will be accepted

If you are an expert who was asked to give an opinion in legal proceedings, note these points:

• Understand the questions in dispute: read carefully the court’s decisions and the questions the lawyer referred to you. The opinion must answer the specific questions that were asked
• Write clearly: remember that the judge is not a professional in your field. Use concrete examples and diagrams where needed
• Describe the tests and the data: set out how you carried out the test or the analysis and which documents you relied on, so that the work can be examined
• Acknowledge the limits of the opinion: if you are not sure, say so. Admitting a limitation increases credibility rather than reducing it
• Be ready for cross-examination: the other party’s lawyer will ask hard questions, sometimes based on a counter-opinion. Prepare the answers in advance, and treat the opposing professional position with respect even if you do not agree with it