I would bet you this isn’t the first time the mom’s been talked to.
Out of curiosity, what would be the basis of the bet?
I remember when my daughter was about 2-1/2, she fell down and dirtied the knees of her white leotard. She stood up, brushed her knees off and wiped her her palms against each other while proclaiming, "Oh tit" (mispronunciation common to toddlers). My wife and I looked at each other and realized that she had probably heard one of us, or some other individual older than her, use the phrase at one time and was trying to mimic the grown-ups for a "proper" situational response.
Kids pick up on a lot and you can't keep them from overhearing anyone around them and letting it run in their developing, high-energy/super-learning-mode minds.
IOW - $hit happens and it's not necessarily a sign that the parenting is below par when it does.