Something doesn't add up. It seems ground beef would be the cause for being sick, if it's not cooked d good enough, or it was left out at room temperature where bacteria can grow.
Chicken is harder to spoil because chicken nuggets or fingers usually come frozen.As a cook, we had to take a course in food safety so things like this don't happen. If anyone ever did get sick, we could be sued or shut down. The Board of Health doesn't like people getting sick.
I would love to go and check out that Red Robin. I could tell you immediately if their kitchen was not up to code.