CP says " the odds of finding an exit are 14283 to 1"*
This would mean he needs to know how many tunnels/branches of tunnels there are and how many exits there are. It is inconceivable that he would know either data point unless he had a map. And if he had a map…
Sure it was a joke - but why have a logic-based robot make a nonsensical comment.
- paraphrasing the quote