"The little 14-year-old from China dropped the ball, baby," he said. "Too excited, went out like stink, died like a pig. Thanks for that."
The commentator was apparently unaware that his microphone was still being broadcast to the world. But followers on social media certainly did not miss the shocking gaffe.
The announcer later apologised for his comments, claiming he meant "no disrespect".
"I would like to take a moment to apologise for a comment that I made last night after the women's relay," MacDonald said on CBC's Olympic broadcast.
"I was referring to a swimmer's performance, and not to them as a person. Needless to say, there was no disrespect intended and I'm very sorry."
Faced with an incredible backlash online, CBC were forced to issue an additional apology, with spokesman Chuck Thompson telling Postmedia on Thursday that MacDonald had made an "unfortunate choice of words".
"We sincerely regret that these statements were made, and that they were allowed to go to air. We moved quickly last night to apologise to our viewers on-air and to our followers on social media," Thompson said.
"To be clear, Byron's comments were related to the swimmer's performance, not to her as an individual. That said, they were inappropriate and an unfortunate choice of words and Byron is very sorry for what he said."
For many outraged viewers, Thompson's severe understatement in describing the commentator's poor word choice simply wasn't good enough, as MacDonald's future job security was questioned.
It is currently unclear what penalty MacDonald may face from his employer over the comments.
-News.com.au
