Yes both dressed very casually................
I guess, it depends where the restaurant is, and what time of day or night it is, for some kind of dress code to be appropriate.
Now, if it was an outdoor seaside restaurant during the day, they would probably fit in with the rest of the diners, but if it was an evening date, then they probably should have taken the opportunity, like most of us do, and put on some nicer clothes for the occassion.
From my experience with restaurants over here, there are generally no strict dress codes, just a bit of common sense and what fits the surroundings...