Try as I have and failed on many occasions to like the local food whereas as I have successfully in Thailand, Korea, Japan, Viet Nam, etc. I never found anything here I'd look forward to having again.
In my usual rants about this also I mention that the food is left out for more time than I would prefer, rather than freshly prepared. Like those Yong Tau places though I'm probably spelling it wrong.
So with this rat incident, one has to wonder how long they were in the food, and for how long or how many times that food was kept in the back room and brought out again.
While it is possible they got into the food during the day, it's unlikely and it probably happened overnight.