I'm not an expert in polling, but polls have margins of error, and pollsters often make corrections to their raw polling to compensate for demographic differences between their sampled population and what they anticipate the actual electorate might look like. So, for any given poll, there are a bunch of assumptions baked into the numbers, any of which might turn out to be false. In other words, when an election disagrees with a poll, that can be a surprise, but it's not an immediate red flag.

That said, many states have laws that allow for automatic recounts when the margin of victory is small enough (typically under 1%). And we recommend that every state adopt risk-limiting audits (the topic of this post!) for all their elections, as a required procedure.

In a high-margin race, a risk limiting audit requires a very small number of samples in order to provide convincing evidence of the correctness of the outcome, so RLAs would be a great thing to adopt.