What umpire should do is to overrule the linesman if it was obvious that the line judge has made a mistake (there is also a service judge on the court who can unofficially help the umpire with descret gesture (for example pointing finger down for in) showing his oppinion about in or out) ... If not, he should go with the linesman, and insist to play on - if any of the players doesn't want to, he has a yellow and red card in his pocket and he should use them ... So, maybe the referee should change the umpire instead of the line judge...
KKK/TBH hit the shuttle into the net which fails to go over, and then they push the birdie over to the japanese. However, teh umpire thought that the bird hit the tape and rolled over to the japanese's side, giving the malaysians the point.
The shot landed in. If there was a line judge, which there is in most tournaments, I would accept their decision. If it was my partner, then I would correct them and agree to lose the point. This has only happened to me once before in any match situation.
In a finals game in a tournament, I was playing against a friend (at the time, he was more of an acquaintance). I hit a shot which felt like it was going out, so I wasn't surprised when my opponent called it out (though it was a tough call). The umpire overruled and gave me the point, but I said that I agreed with my opponent's call and gave him the point and the serve. I think a player should have the right to give the point to their opponent if they think that the umpire made a mistake, though whether or not they exercise is a different matter. This occurred in the second set after I had gotten a second leg cramp, so I figured I probably wasn't going to win the match anyway. Had this been at 18-18 or 19-19, I would've probably taken the point and just considered myself lucky. There's a bit of luck that's sometimes part of the game, but that's just how it is.
Close calls always happen, and mistakes also always happen, as an umpire myself, I would have to respect the calls of my line judges (if any) unless I'm 100% sure their call is wrong, that is the rules of the umpire. If there are no line judges, but the umpire disagrees with the player even though you would give the point to your opponent, just accept that fact and play on, like I said, mistakes happen. If for sure you're 100% sure that the umpire made a mistake, be a fair sport and hit into the net then.