3. When is expert evidence typically necessary?

3. When is expert evidence typically necessary? 

Expert evidence is standard or necessary in the following types of disputes: 

1. Professional and medical negligence: Expert evidence is almost always required to help the court determine the required standard of skill and care for a professional and whether the defendant’s actions fell below that standard. In medical negligence, it is specifically required to establish liability and causation. For more information about professional negligence and medical negligence, please refer to “Professional liability” and “Medical Negligence” respectively. 

2. Foreign law: In Hong Kong, foreign law is treated as a question of fact that must be proved by evidence. A person suitably qualified by knowledge or experience is needed to testify as an expert on the law of any jurisdiction outside Hong Kong. 

3. Industrial and complex accidents: In cases such as industrial accidents involving specialized machinery, experts are necessary to explain technical causes. 

4. Construction of technical terms: Experts may be necessary to explain words or terms of science or art in a document that the court must construe. 

5. Handwriting and document genuineness: Expert assistance is required when the court or a jury is asked to compare disputed handwriting with a genuine sample.