I served contaminated cake to 40+ people
Why would you decide to serve something like that to people?
Because I wanted to get rid of my friend's expectations
It's wrong to knowingly serve contaminated food to anyone. You should never try to intentionally make people sick.
It is not like they got sick.
They could have though and you wouldn't know if anyone got sick or not later on. You shouldn't try to make people sick and serve them food that has been contaminated. You should be more responsible towards people.