(CNN)--Moments after George Floyd was taken away in an ambulance last May, former Minneapolis Police officer Derek Chauvin was confronted by a witness who took issue with Chauvin's kneeling on Floyd's neck.

"That's one person's opinion," Chauvin responded as he got into his squad car. "We had to control this guy because he's a sizable guy. It looks like he's probably on something."

The short clip from Chauvin's own body camera, played in his criminal trial Wednesday, represents the first time the public has heard the ex-officer's perspective in the 10 months since Floyd died under his knee, launching a worldwide protest movement.

Charles McMillian, the 61-year-old witness, testified that he observed Floyd's arrest on May 25, 2020, and that he encouraged Floyd to comply with police, repeatedly saying, "you can't win." As Chauvin knelt on Floyd's neck and Floyd cried out for help, McMillian can be heard on video telling police to "get your knee off his neck."

After Floyd's limp body was taken away, McMillian had a short conversation with Chauvin because "what I watched was wrong," he said.