They didn't have an "arbitrary shy Trump voter" factor. That's not how they did it. They observed that Trump voters were less likely to answer polls and tried to get at the data other ways.

Also, who cares about 50-state results? One of the key points Trafalgar's founder has made is that polling is a state-by-state exercise. All pollsters use data to estimate e.g. turnout among different demographics. National pollsters use things like exit polls, but Trafalgar digs into state-level voter registration data.