I mean, not to be argumentative, but your personal opinion doesn't change the definition of the term. The first example on Wikipedia's article on it is "the old man the boat." Again, that's only one word, but it turns out there isn't a minimum word-backtracking-count to qualify.
I understand how the misinterpretation happens, but I personally don't think a single misinterpreted word is enough to make a garden path sentence.