According to USA Today, that woman was LeBron's mom!
Ms. James came roaring into the action in the second quarter when her son was wrapped up on a breakaway dunk attempt by Paul Pierce.
Kevin Garnett tried to calm her down, but it was LeBron who got the job done.
"I told her to sit down, in some language I shouldn't have used," James said. "Thank God today wasn't Mother's Day. All I could think about is her. ... I know my mother. It's fine, we're good."