In some cases the court may mandate that a Single Joint Expert is instructed or the parties may agree to the appointment of a Single Joint Expert. If a Single Joint Expert is appointed then the parties must agree and/or exchange instructions to the Expert Witness. There are some limitations on contact with a Single Joint Expert, but essentially the same approach applies to the selection and appointment process.
From a solicitor’s point of view, a benefit of instructing a Single Joint Expert is that once you get their opinion, everyone knows where they stand and can rely on that opinion. There are also no adversarial views between Expert Witnesses.
The main disadvantage is that a Single Joint Expert is no one side’s Expert Witness. Solicitors can’t have private conversations with the Expert Witness and all communication, verbal and written, must be sent simultaneously to both parties. If the parties disagree on facts or the terms of an instruction, separate instructions must be delivered and the Single Joint Expert has to navigate this and consider both sides when reaching their opinion.
Alternatively, parties may have separate Expert Witnesses in the same discipline. If you do, it’s important for both Expert Witnesses to have access to the same documents and can avoid embarrassment in the witness box later.