The article does not mention this, but it was later found out that a disgruntled worker who was on his way out defecated into a jar or bag (don't remember the details) and then mixed it into the salsa that was distributed over that weekend when this outbreak occurred.

It was what eventually caused Garcias to close in Provo.

Here is the article. https://www.deseretnews.com/article/123022/OUTBREAK-OF-INFECTIOUS-DISEASE-IS-TRACED-TO-PROVO-RESTAURANT.html

Of course as teenagers in high school, we all started making up jokes like:

"Man this salsa tastes like crap".
"Flush twice it's a long way to the kitchen".
"Black banana in my salsa" singing.

I look back now and feel bad for the owner. The one in Layton is still open and he was expanding his business down into Provo when this occurred.