Well, rules can be simple and there can be few exceptions and people will still screw up, so I don't think that anecdote proves anything. In any case, my claim

Well, rules can be simple and there can be few exceptions and people will still screw up, so I don't think that anecdote proves anything. In any case, my claim is that there is exactly one possible pronunciation per correctly spelled Spanish word. The opposite direction is not quite 1:1, but again, it's very close, and anyway it's far closer than English.