Not to rehash anything that anyone has said, but I don't know if it's clearly been stated, but the command rm -rf / *will* attempt to erase every file on the server, without confirmation.
If you had the privlege to run the "rm" command, and it took, then chances are pretty high that you completely toasted their server.
And not to sound like a jerk, but if you're running around on servers (that you don't own or manage) executing commands you don't know about at will, you should probably take a step back from a penetration specialist role and get some more basic experience under your belt.
Poking at security since 1986. +++ATH