The scenes sparked fury within the City support, prompting one man to pelt a coin at defender Rio Ferdinand which drew blood, but Giggs has made it clear that the United players were not even aware who was who in the stands.
"First of all it's tough at City because their hardcore supporters are right next to our supporters," he told the club's official pdcast.
"When they are so close together how can you determine whether you are just celebrating in front of United fans?
"When you score a goal like that you don't have control of yourself. As a player you want to celebrate.
"If you just scored a goal and walked back to the centre circle, United fans would want to know what's going on there."