I have also seen people who do not like their work or who trust themselves and generate very serious problems by offering their services to others, it happens and will continue to happen and many people in the world will be affected without us knowing it. It is good that in your case you were attentive and it was not a drug that could do any harm.
But what I know is that at some point either the person who works in that place or the company itself is affected or some other company or person who offers a better service arrives and they end up going bankrupt.