stolen Mac

my mac was recently stolen. from my recollection it was never connected to Find my and I disconnected my mac from my icloud before it was stolen. However, it must have been connected because I had the option to lock my Mac despite the location not being available. It took awhile but now it says locked. Is it possible for it to say locked and not really be locked? The option to erase everything is also not available to me but I'm curious as to why. Would I have to erase it and then lock it? Does the mac have to be online for me to choose the erase option?