Coincidence in fiction

The other day, our car broke down on a busy dual carriageway. While my husband was on the phone, and the kids and I were standing in the rain on the grass verge, a good Samaritan stopped and offered us a tow home. At that very moment, my brother-in-law passed by, and gave me and the kids a lift home while my husband was precariously towed.

My brother-in-law was only passing because the route he'd been taking to work was dogged by tractors, and his first meeting of the day ran over.

It occurred to me at the time that we'd been very lucky. But then it occurred to me, because I'm always on the look out for story ideas, that the coincidence of my brother-in-law passing would be a step too far for fiction. Luck is not a plot devise. Or, at least, that's what I've been told by all those 'How to Write...' books.

In fiction, the characters have to get themselves out of trouble - in fiction, being rescued by a knight in shining armour should be reserved for Snow White and Rapunzel (although even Rapunzel had the foresight to grow her hair and, therefore, help herself). When contemporary characters are in peril, too easy a solution makes the reader feel cheated: a lottery win when we were never told they played, a screwdriver pulled from an oddly placed pocket of an evening dress... In fiction, we'd probably have been left with the choice to wait or walk - neither very appealing.

So, question, do you feel cheated by a plot that's too easily/coincidentally resolved?