"No one would design a system like this": UHG CEO Witty says U.S. health care is "flawed"

UnitedHealthcare CEO Brian Thompson was gunned down in New York City last week .

Andrew Witty wrote a New York Times op-ed about the health care system in the U.S. "We understand people’s frustrations with it,” he said.

Witty has condemned public reaction to the killing of Thompson .