Hemoglobin (Hb) transports O2 from the lungs to working tissues, including muscles, the brain, etc., and transports CO2 away from those tissues to the lungs to be exhaled. The reason Carbon Monoxide is so lethal is that its binding affinity for Hb is more than 200 times greater than O2's affinity for Hb. It doesn't become converted into CO2, it shuts down the O2/CO2 transport system. If your tissues can't get fresh O2, they can't make ATP (energy source); they die; and if the damage is widespread enough, or affects a critical system, that's it... you die!

CO also has another toxic mechanism of action. It's able to penetrate the outer layer of cells (lipid bilayer) and enter cells. Then it acts as a neurotransmitter and binds with the iron molecules in an enzyme (guanylyl cyclase) that regulates the second messenger cyclic GMP. cGMP then amplifies other processes to stimulate action within the cell. This is a natural process that is finely regulated in the brain and elsewhere. If, however, this pathway is activated inappropriately, and for too long, it can have serious consequences that depend on the degree of exposure.

Putting all this physiology aside, you've probably heard that CO is lethal because of people using it to kill themselves by breathing the exhaust of a running car in their garage. CO poisoning is also a major cause of death after people are "rescued" from burning buildings. They're given hyperbaric oxygen treatment to try to displace the CO from their Hb.

Sorry, but I don't know much about food processing, but I doubt CO would penetrate deeply into meat without a functional circulatory or neural system. Hope this helps,
Rick