I Noticed That Some Of The Lettuce I Had On

I noticed that some of the lettuce I had on my salad at lunch today seemed wilted. I picked out a slimy looking piece and every other questionable piece. It tasted fine (though hard to tell when covered in dressing). It was a salad bar in thr cafeteria at work. I had lunch at 11:45am and it's now almost 11pm. I'm worried about my odds for food poisoning. It's been almost 13l2 hours and I feel mostly ok, just some gas in my lower intestine. Should I be worried?