Ball lost or not?

Question
Our course is plagued by rabbits. We get a free drop if we land in a rabbit scrape or hole.
Today, my playing partner's ball slipped out of his fingers as he was retrieving it from a rabbit hole. The ball dropped back into the hole, but this time rolled out of sight and out of reach.
Does he get a free drop with a second ball or is this now a case of lost ball?
Thanks
Chris

Answer
Dear Chris, thanks for the question.  Because your course has allowed for a free-drop with regard to the rabbit problem, I cannot really answer this.  It would have to be up to the course who offered the local rule exception in the first place. It is always within the course's discretion on how to proceed with regard to their own local rule or rules, outside the normal spectrum of the USGA.  I would ask the local professional or manager on how to proceed; I would hate to offer the wrong solution here.  Thanks again for asking, good luck and remember...

Love the game,
skipper