Realiism in writing?

I just read an article about a bunch of PETA activists who showed up a motorcycle event throwing water balloons filled with red water to protest them wearing leather. Bikers are sensitive people and protective of their leather which they consider the only attire that can truly handle the wind and cold when riding. The title of the article was "When you mess with the bull - you get the horns." I don't know what they expected to happen but police found them wrapped in duct tape and thrown in dumpsters, and one hapless soul was duct taped to a tree and used for a urinal. I'm thinking that they just did not think this through before protesting this group and should have stuck to little old ladies wearing animal fur.

Why am I talking about this? Because it reminded me how often I see things in real life that simply would not be believable if written into a book. It happens all the time.

Getting the realism right without becoming unbelievable to readers can be a problem. Back in my early writing days I had a New York editor reject me because the western-themed book I was pitching that had some rodeo scenes in it was "just not how cowboys would talk in a rodeo." When I asked if she had ever been to a rodeo she said no. I've ridden in them, and even put one on for five years as the event manager. Which one of us would you guess would know more about appropriate dialogue?

I was, of course, but actually she was right. As I learned more about the craft I learned that we should never try to 'reproduce' dialogue but should hint at it. Large stretches of dialogue in a heavy brogue gets very tiresome to read very quickly. I would have gotten that explanation, but telling me I didn't know how they talk was not the right way to put it. But again, too much realism can put editors off and cause a project to be rejected.

I would love to see some feedback on this. What have you seen in real life that people simply would not believe if we made it up and wrote it into our books?