Respiratory expert says preexisting conditions did not cause George Floyd's death

• "There was virtually very little opportunity for him to be able to get any air to move into the left side of his chest," Tobin said.
• "He's jammed down against the street. And so the street is playing a major role in preventing him from expanding his chest," he added.

But the defense has argued that Floyd's preexisting conditions — including a case of COVID-19, drug and nicotine use, and a small abdominal tumor — were factors that pushed his life over the edge during his arrest.

What he's saying: "Floyd died from a low level of oxygen, and this caused damage to his brain that we see and it also caused a PEA arrhythmia that caused his heart to stop," Tobin said on Thursday.

• Tobin added that fentanyl present in Floyd's system would not have been a cause of death, either.