The German club's president was speaking at a dinner after the game in Hotel Rey Juan Carlos close to Camp Nou and stated that he could not work out whether he was shaken, sad or angry about the result.
Bayern were beaten by four first half goals as Barcelona produced an incredible display to leave the Barvarian outfit with little chance of qualifying for the Champions League semi-finals.
"I saw our old friend Udo Lattek at half-time and he was crying. I do not know if they were tears of rage, tears of sadness or of pain," AS quote Rummenigge as saying..
"But it was significant after the lamentable display that we saw out there.
"We have lived through a bitter moment for Bayern here in Barcelona, without doubt. I want to talk straight and say that what we have seen has been ridiculous.
"I have to say sincerely that I do not know how I feel most: shaken, sad or angry after what I saw.
"We have been taught a lesson and that lesson hurts."
Rummenigge did not want any hasty calls for people to go or for changes to be made at the club, and hopes that they can regroup and aim to win the domestic title.
"With this result it is obvious that we are out of the competition. At this difficult moment we should remain rational and not exaggerate things," he continued.
"Above all we must not make meaningless and spontaneous decisions.
"We have to stick with what we have done well this season and try and win our last eight games in the Bundesliga and achieve our goals.
"We are a proud club and that pride has been dented tonight, above all in the first half. I can only ask that in the coming weeks the team gives everything possible."
Lucas Brown, Goal.com