Dr. David Katz - One possibility is that the administration of oxygen displaced carbon...

One possibility is that the administration of oxygen displaced carbon monoxide from his blood and so it's in his body but we're [they're] not measuring it yet. Another possibility is that the temperature in the mine, about 55 degrees, can actually affect this blood test, which is challenging to do. And, of course, it's possible, that one miner had a working oxygen mask and was protected from the carbon monoxide to which the other miners were exposed and there may have been a mix of gases.