Good point, important not to lose sight of this. And additionally, the most restrictive rules of any segment apply to the whole itinerary, both as discussed upthread.

So in this case, the OP doesn't appear to have any recourse.

However, the lack of clarity in the fare rules is something we should all watch out for. Read carefully!! And, at least as importantly, not only must one read what the rules say, but one must also be aware of what they do not say.