Commenting on the flap, the International Olympic Committee pointed to London officials.
"It's a matter for the organizers," IOC spokesman Mark Adams said.
The players walked past reporters after the match still in uniform without stopping. Two were carrying flags — the correct North Korean one.
North Korea and South Korea are bitter rivals. The flag mix-up comes amid high tension on the Korean Peninsula following a North Korean long-range rocket launch in April and repeated threats by Pyongyang to attack the South. Seoul and the U.S. have called the launch a cover for a test of banned long-range missile technology. North Korea says the rocket, which broke apart shortly after liftoff, was meant to put a satellite into orbit.
Wednesday's match started 1 hour, 5 minutes late. Fans were confused at first, then turned to doing the wave and finally started booing as they became increasingly restless.
An announcement was eventually made over the public address system about 20 minutes after the scheduled 7:45 p.m. (1845 GMT; 2:45 p.m. EDT) kick off, apologizing for the delay and saying it "was due to an issue behind the scenes. We're trying to resolve it and we'll keep you updated."
To pass more time, music was pumped from the speakers. Players from both teams finally emerged onto the field about 40 minutes after the match was supposed to begin. The players warmed up again for 10 minutes before they returned inside the tunnel to be led out again for the national anthems.
"It was very difficult after the incident," Colombia coach Ricardo Rozo said. "We had to wait and warm up again. It affected the mood because we were ready for the match.