I've found a lot of inconsistent documentation on single user mode. I don't need to use it often, but I get curious, and I remember not being to use shut down commands in single user mode and pressing the reset button. Is there a better way to leave single user mode after resetting passwords?
What do you have running in single user mode? Are databases running etc. etc. If you are worried then I would run
shutdown -i 0 (though depends on what flavor you are using)