Sung said after the Chinese set the precedent, the South Korean pair in the second match deliberately emulated the Chinese tactic because they did not want to face their team mates in the quarter-finals.
"Because they don't want to play the semi-final against each other, so we did the same. We didn't want to play the South Korean team again," he said.
"They (the BWF) should do something about (the format)."
Review promised
Paisan Rangsikitpho, a technical delegate at the tournament, told Reuters before the second match that there would be a review and held out disqualification from the tournament as a potential maximum punishment.
"We will have a real discussion tonight to see what has happened," he told Reuters.
"If it's true what I hear, this is a shame and I don't like it. And I'm not going to accept anything that I don't like at all. It's not in a good spirit.
"It is (embarrassing) at the Games. I apologise to the public, I apologise for everyone and I am not happy.
"If we have to stay up all night, we will have a serious meeting."
Fans booed as shuttle-cocks were hit long in both matches with serves dumped into the net.
China's Yu claimed she and her partner were just trying to conserve their strength for the knockout rounds.
"Actually these opponents really were strong. This is the first time we've played them and tomorrow it's the knockout rounds, so we've already qualified and we wanted to have more energy for the knockout rounds," she told Reuters.
"Really, it's not necessary to go out hard again when the knockout rounds are tomorrow."
Her South Korean opponents declined to comment.
Other players at the tournament expressed their disdain at the situation.
"If it was the case they wanted to purposefully lose, then it's a big shame ... It's absolutely stupid and shameful sport, basically," said Germany's men's singles player Marc Zwiebler.
"I can understand the motives but that they have the guts to actually stand in a crowded hall and put such shame in the game, it's such a bad image of badminton." — Reuters