Well getting up out of the map solo is incredibly hard, then you have to take into account that the destroyed rock won't respawn, so every go will take about 3 minutes to prepare.
You know, that's what I miss about Halo 2. All the maps had little hiding holes you could sometimes get into.
A glitch exclusive to Halo 2 where you could jump in certain spots and "bounce" really high into the air, often to the point where you could hit the top barrier of the map. People performed superbounces to get out of maps and to get into hiding spots. Example: YouTube- Zanzibar Super Jump - top of big wheel