Dr. Dick Miller CNN The psychologist who testified in defense of the 16-year-old drunk driver who killed four people and received no jail time is defending his controversial stance that the boy was afflicted with "affluenza" — meaning the boy's wealth caused him to dissociate his bad actions from consequences.

On "Anderson Cooper 360" Thursday evening, Dr. Dick Miller got into a frustrating exchange with host Anderson Cooper over the sentencing of Ethan Couch — he faced 20 years in prison but instead got 10 years probation — along with the rationale behind a recommendation for treatment instead of punishment.

"I don't believe going to the penitentiary was best for him or the state of Texas, and [the judge] concurred," he told Cooper.

Cooper brought up a similar case ruled on by the judge a year prior, in that a 14-year-old African-American boy who killed one person was sentenced to 10 years in juvenile detention.

"It had nothing to do with his color. It had nothing to do with his wealth," Miller said of the reasoning behind his recommendation for Couch's much more lenient sentence. "[It] had nothing to do with any of those things. It had to do with what I thought was best for him and the state of Texas."

In one of the more heated exchanges of the interview, Cooper and Miller got into a debate over use of the term "kill" when talking about the four people who died in the accident (begins around 5:30 mark in second video).

"If you kill four people, you can't use that as an excuse, can you?" Cooper asked of the doctor's "affluenza" defense.

Here's a partial transcript of what followed:

MILLER: "When you use the term kill, and people out in America hear that, it implies that there was some motive, that the motive was not good. I think these parents, I think this kid, I think that all of my patients, about 90% of them — their motive is totally honorable like yours is tonight.

Like you, you know, all the people I've watched on CNN, I'm not going to question their motive. I think their method leaves something to be desired. When Nancy [Grace] says 'he murdered four people' — I'm thinking try another method Nancy, you're an attorney."

COOPER: "Are you saying he didn't murder — he didn't kill four people?"

MILLER: "He did not murder four people. It's a legal term."

After dispensing with the term "murder," Cooper asks, "He killed four people, yes?"

"Four people died," Miller said.

"Four people didn't just magically die," Cooper said. "He slammed his vehicle into four people. Correct?"

After a rather exasperating back-and-forth, Miller finally admits that four people were in fact killed by Couch.

Couch's blood alcohol level was three times the legal limit when he plowed into four pedestrians last June, the LA Times reported. He was driving along with seven people in his Ford F-350 truck, and they had reportedly stolen two cases of beer from a store.

You can watch the interview below:

Part 1:

Part 2:

Part 3: