Sorry, but this is contrived. One can speak clearly without resorting to a formula. The story contradicts itself. The author describes at length the process he had to go through to decode this supposedly clear communication. The one person without a vested interest in the formula (his wife) just found it puzzling and annoying. Besides, it's obvious how to communicate the information "I've been in an accident, but I'm…
That's a breakdown in the kid's/family's communication. It is simple to say, "I walked in the rain." It conveys the exact same piece of information--I'm wet because it was raining outside, and I was outside without something to keep the rain off of me. There are numerous other ways to say the same thing without sounding backwards.