Spirit of Redemption is a great talent, and for a little while you're an awesome looking babe (if not completely corporeal), rather than an ugly troll or whatever. However, it can be annoying if you're soloing or you die in a battleground with no one else around.
Lonely Spirit automatically cancels SoR if you're by yourself. It checks to see if anyone in your raid or party (or their pets) is in healing range, and also your target if they are friendly. If anyone is in healing range you will be the SoR, otherwise it cancels it.
Slash commands are:
/ls - activate or deactivate Lonely Spirit
/ls or - Override the next auto-cancel (lasts until you next die)
/ls help - Print this help
There is also a key-binding available for the override function. If you are fighting and think you may need SoR, press your bound key and you will be the SoR.