I had a similar reaction to an upscale seafood restaurant...
I was totally fine before I went in, 4 hours later I was hurling and praying to the porcelain gods. I called the restaurant and they said..."oh no, you didn't get sick here, food poisoning takes XX hours...We are innocent, blamless, and guilt free. How dare you call us and insinuate such filth to us..."
I paraphrase, but you get my drift.
Yes, you probably got sick at the restauant, and yes, they will tell you it could not possibly have been them.
MY MISTAKE: I didn't call the food inspectors right then.
If they don't give you satisfaction, call the food inspectors.