Because the polling majorly favored Biden and the results showed far more Trump votes than anticipated could rationally be interpreted to mean that mail-in ball

Because the polling majorly favored Biden and the results showed far more Trump votes than anticipated could rationally be interpreted to mean that mail-in ballots were flawed in a way that favored Trump. I'm not claiming this is the case but providing an example of how subjective and spinnable any set of facts can be made.