Technicalities are important when we are talking about a life and death situations.
Yes, theoretically, the buddy heater will shut off (due to lack of oxygen)and therefore will not produce CO that will reach a dangerous level.
My point is that the buddy heater does not have have a CO shutout valve and proclaiming that it does could lead someone into dangerous situation thinking that they didn't need a functioning CO alarm because they were using a buddy heater.
Ever thought that there is a possibility that the CO could be coming from another source, or that your camper could have a high CO level before you turned on your buddy?
Lots of technicalities could kill you, but hey don't worry about it because some guy on the internet told me that it had a CO shut off valve and that I don't need to worry about technicalities.