A witness is nice, but I don't think it's necessary for the state records that The Hawaii Fishing News keeps. Just turn in the paperwork and a picture.
And it's "Jungle Rules", not IGFA rules here in Hawaii.
http://www.hawaiifishingnews.com/records.cfm
When we took Rae out that day to "set a new state record", I had a postage scale and weighed every bluegill she caught. She took the heaviest fish to a certified scale at the store for the "official" weight. (she kept that fish in their Koi Pond for over a year)
She caught her record fish on her third cast... over by place where the people are building the new deck in their yard. (big concrete pilers just up the North Fork on the right) Where we've been feeding dog food to the RD.
