Well, I have a daycare, and yes.. I hate it when the kids infect us with something. But, while I grumble about it, I don't ever think the parents do it on purpose. Most of the time, it's the daycare getting the kids sick. It's just no fun to be sick.
Wait... once.. I had a mom come home from Disneyland with a very sick kid.... she wanted to meet a friend for lunch, so she called and asked if her son could come over for a few hours. I said "sure.. we miss him anyway". So, within the hour, he had the worst smelling blowout I have ever seen. I called her, she came over.. but, it took her an hour to get there. (she was three miles away) and within 24 hours her son was in the hospital with Rotavirus. She actually had the nerve to call me and ask if any of my kids had it... "Uh... no.... you were in California for the last two weeks... maybe he got it there?????" Then, she remembered that he'd actually been up all night the night before with vomiting and diarrhea. "Yes.... maybe that wasn't a coincidence"
But, since you came and picked your child up very fast, I doubt anybody thought anything other than "Ugh!". It's not your fault.. you didn't do it on purpose, and one day, you will all catch something from daycare. It's part of living in society.