I accidentally untarred archive intended to be extracted in root directory, which among others included some files for /etc directory.
I went on to rm -rv ~/etc, but I quickly typed rm -rv /etc instead, and hit enter, while using a root account.
I think he pressed up after having run that command to see what he wrote wrong.
Unlikely, as the v flag would leave a list of all deleted files before the active prompt.
Edit: I get it now. The ls was executed after deletion