Being retained as an expert witness in legal matters serves as an indication of the regard in which a lawyer's expertise is considered by the legal community. Mr. Hartog has served as an expert witness in a variety of legal proceedings. He has testified as an expert at trial regarding professional negligence, as well as at trials concerning breaches of the standard of care applicable to trustees. Mr. Hartog has been retained as an expert in more than 100 cases, has been deposed more than 50 times, and has testified at more than 20 trials. His recognized expertise has made him a desired witness in a variety of cases concerning trusts and estates law in states beyond California, as well as in cases throughout the state.