Liability disclaimers and waivers are not always iron-clad. In addition, under some states' laws, you cannot ask someone else to waive your liability. So that you don't get caught short in either of those two scenarios, it's strongly advisable to have insurance in place to cover those kinds of claims -- in addition to the waiver.
Another benefit of the insurance is that some policies will also cover the defense costs...which could otherwise drain your operating cash.
Nina L. Kaufman, Esq. is an award-winning New York City attorney, edutainer and author. Under her Ask The Business Lawyer brand, she reaches thousands of entrepreneurs and small business owners with her legal services, professional speaking, information products, and LexAppeal weekly ezine. She also writes the Making It Legal blog.