I was on a radio talk show many years ago and we were discussing how someone could influence the outcome of a match. It could be football , rugby or any sport. It is hard for one player on a large team to have much influence though. You would need at least a third or more to be in on it and that means more lips that could talk. This was the time of Bruce Grobelaar and the scandals surrounding his betting.It would be easy for a goalie to make an error to change the scoreline, but it couldn't happen too often if he wanted to keep being selected.
I think at the time the one who had the most say and who could change it wouldn't be a player, but the referee. The way the laws of various sports have been written there are certain grey areas and human error can be blamed for certain decisions. It is how the match official interprets the law at that given time.
With the introduction of VAR in football,the wicket review in cricket and the third match official in rugby it would be much harder to pull off today. I know 10 or 15 years ago in rugby it wouldn't have been too difficult to get something wrong on purpose favoring one of the teams. It could be something so small yet so important. I used to enjoy watching the old games from years gone by, but it is too obvious that the home referees had too big a say. The 1974 Lions in South Africa were robbed by home town whistle blowing.
I am all for questioning the officials by use of replays and whatever technology is available as it is the correct result that we are all after. There is nothing worse than having a result that is wrong due to human error. Saying that errors are still made in the biggest of arenas for instance the latest Cricket World Cup where the officials cocked up massively. It was something out of the ordinary that happened, but they still got it wrong.
I read an article today which got me onto this subject in the first place about an NBA official who was part of a mob betting syndicate. He didn't change the result but influenced the spread of points between the two teams which can be more lucrative than betting on the win. I am hoping more and more technology comes in so it doesn't allow for this, but still keeping the human official as that is what is still important.
One other reason is why I am still in favor of keeping the human element is for safety reasons. Only someone who knows and understands the game can keep it safe for everyone playing.