A professional wedding photographer should have both professional indemnity insurance and public liability insurance. Compensation cover should be between £2 million and £5 million, and they should be happy to show you their insurance documents if asked.
I have the above not only to protect my equipment, but also protect against any claims from a wedding day if someone trips over my tripod or I pose someone in a way that injures them. Sometimes venues will ask for insurance too, despite having their own.
I'm not always a fan of insurance for personal things, however for a business I think it's a necessity. I'd be wary if your photographer doesn't have it as accidents happen!