Yes, of course in retrospect the poll was flawed. It doesn't matter that this is a rare event - your strategy would make it even rarer. And calling this out for being a black swan event is bizarre, as you keep bringing up another black swan event; the 2000 Presidential Election in Florida.

In the 2000 election, "Gore was leading Bush and third parties with 44-42-4 among registered voters" in late October according to one poll.

In Minn. it was Humphrey 35%, Coleman 34%, and Ventura 21%. You posited "Humphrey was way worse than Coleman". That's inverted compared to 2000. Assume that a Ventura supporter considered Coleman way worse than Humphrey.

In that case, what should the Ventura supporter do? I believe you would say to vote for Humphrey. By ignoring that advice, the Ventura supporters ended up with Ventura.