I'm reading Batman Knightquest, in Detective Comics #668, Tim Drake finds a way to the batcave after Jean Paul as Batman seals other entrances (including the one Tim build under his house), he (Robin) says, "Funny. This is how I got this job. I found my own way into the batcave". As I remember, it's not mentioned in "A Lonely place of dying" that he finds his own way into the batcave, he even express surprise as Dick and Alfred are showing him the cave.
Does he have another origin which includes him finding his own way into the cave or maybe he is simply talking about that time he planned a entrance way to the batcave from his own home (the one who was also shut by Paul)? Anyone care to explain? Thanks!