Dr. Martin Tobin, a pulmonologist, said during rebuttal testimony that the opinion of defense expert witness Dr. David Fowler regarding George Floyd's potential level of carbon monoxide in his blood was "simply wrong."
Tobin said medical records showed Floyd's oxygen saturation was 98% when he died. Prosecutor Jerry Blackwell asked him: "Does that tell us anything whatsoever about what the carbon monoxide content could have been at a maximum?"
Tobin said: "Yes, it does. It tells us that if hemoglobin is saturated at 98%, it has – for others is 2%. So the maximum amount of carbon monoxide would be 2%."
Why this is important: Dr. Fowler testified that it was possible that carbon monoxide ingestion could have been one of the causes of Floyd's death. He based this on observations of Floyd being pinned on the ground near the tailpipe of the police cruiser that officers were trying to get him into. Fowler acknowledged that he had not seen any data on Floyd's carbon monoxide levels prior to testifying.
During his testimony Fowler said that it was his opinion that Floyd's carbon monoxide levels in his blood could have increased by 10% to 15%. Tobin said that assessment is "simply wrong."