As reported in the Insurance Journal, this is an example of why it is difficult to give a definitive answer about how much professional liability insurance coverage you need. Granted this is an extreme example but $214 millions attorney malpractice suits do happen. Even for a 450 remember firm such as the former firm of Kaye Scholer this is a large demand. It would be interesting to know what it settles for, but likely we will never know.
For details on attorney malpractice suit click on Rennert v Kaye Scholer
Every law firm needs to look at the types of clients and the size of the cases handled.. Remember it is not the average that you need to worry about when determining your liability limit. It is also not the number of cases or clients you have. What you need to determine is if you make a mistake or are alleged to have made a mistake with your largest valued case, how much can that mistake cost. Normally an insurance agent cannot tell you this, the firm needs to determine.