Comment by lloeki

Might be. Some terminal emulators save logs. "Unlimited scrolling" often goes to disk, possibly in a file, possibly in swap (Terminal.app makes it stay in memory, which once consumed 3GB of RAM for my long-lived "rails server" tab). iTerm2 allows you to navigate back in time, while Terminal.app saves some data on quit to display on restore (if OSX autosave is enabled).