Well my SB turned on in my bag!!! I picked up my slipcase and it was warm. I knew right away the stupid SB was running in the case. I really thought we were past all of this now. Every other computer in the world can turn off and stay off with the lid closed. geez
Most likely it never went to sleep in the first place. I have this a few times. Shut the lid down and shoved it in my bag only to take out a few hours later with screen on and a nice hot bag. I now shut down before closing the lid to be sure. I could have also changed the behavior for the lid close to hibernate I believe.
To be safe, I enabled hibernation mode and manually put it in hibernate before I take it anywhere. Yes, it takes a few more seconds to boot, but better that than find a hot plate and dead battery when you need it.