You deleted a log file mid-session, a running process is still writing to it, and ls shows nothing, but the data is still there, and you can get it back before the process closes.
Linux deletes files the way most people assume is permanent, but what the rm command actually does is remove the directory entry and decrement the file’s link count, and if any process still has that file open, the kernel keeps the underlying inode alive until the last file descriptor pointing to it is closed.
That window between rm and process exit is your recovery window, and on a live production system, it’s often wide enough to save you.