Judging boxing is difficult enough even without that. Judges see it in real time, with no replays and no slo-mo. Most human beings who follow boxing have opinions; they tend to make you watch one fighter more than the other. You miss things doing that.
Judges, of course, are trained (or should be) to be more objective than that - but the pressure exerted by a wildly enthusiastic hometown crowd (let's leave corruption and dodginess aside for now) can bend objectivity and opinion.
Case in point 2: Jeff Horn (Australia) v Manny Pacquiao (Philippines). This welterweight contest in Brisbane this month ended in a surprise points decision to Horn. Even though an ageing Pacquiao is clearly past his best, respected boxing trainer and commentator Teddy Atlas headed the disbelief after Pacquiao landed almost double the number of punches Horn had, surely the final arbiter.
"They gave a win, a huge win, to the local kid for trying hard," he yelled. "You're not supposed to get it for trying hard. You're supposed to get it for winning and I thought Pacquiao won the fight, if you go by the real rules of who lands the cleaner punches." The great Lennox Lewis also could not understand how Horn won.
We can discount the WBO's hollow "recount", using five independent judges to review the fight; the WBO said it wouldn't alter the result even if the judges found Pacquiao had actually won. To no one's surprise, they upheld the original decision.
When Parker won the WBO crown against Andy Ruiz last year, a disgruntled minority also hollered "hometown decision". They based it on Ruiz stalking Parker; judges, particularly American judges, often place much store on the aggressor.
But moving forward and being effective are two different things. It all comes down to scoring punches. At the time, former middleweight boxer and now analyst Frank Lotierzo pooh-poohed the whingers, saying Ruiz won only three, maybe four, of the 12 rounds: "Parker boxed him, he moved him, he turned him in the corners, Ruiz just plodded and came forward and didn't let his hands go."
One judge even scored it a draw - a result Lotierzo found ludicrous, demonstrating the subjective divide in scoring fights.
But Parker has no more hometown advantage. He has also had to cope with the Duco "divorce". After an average showing in his last bout, he has also suffered British boxers calling him out as they sense an easier route to a world title.
He needs the Fury bout and at least one or two more, possibly against pumped up cruiserweight Tony Bellew or David Haye, to build up his profile in the UK before a mooted unification fight against Joshua about this time next year.
But maybe Parker might have a crack at WBC champion Deontay Wilder of the USA instead. Some may consider the enormous Wilder (2.01m, 105kg) too big and strong for 1.93m Parker and he certainly has a dangerous right hand.
However, Evander Holyfield - the only four-time world heavyweight champion - was 1.89m and saw off behemoths like George Foreman, Buster Douglas and Riddick Bowe.
Wilder can also be a bit wild; his looping punches offer opportunity for a fast-hands, fast-moving boxer like Parker. Wilder may be a better bet for Parker than Joshua when he eventually seeks a big-name opponent.
That would also give a focus to Parker's campaign which must, in the name of credibility, intersect with moves to unify the WBA, WBC, WBO and IBF titles. If he simply uses his WBO title to pluck low-hanging fruit, it will seem inconsequential - especially with the division sparking into life with Joshua, Wilder, Tyson Fury, Klitschko and others squaring up to be in the one ring that rules them all.
Parker has yet to show he belongs in that company. Now, if only he had hometown advantage...