The 25-year-old returned to Norway for what should have been a routine Champions League win for the Premier League giants.
Striker Kasper Waarts Hogh had the home side 2-0 up thanks to two goals scored in just two minutes before Jens Petter Hauge made it three just ahead of the hour mark.
Rayan Cherki scored shortly after, but Rodri’s straight red card made a comeback all but impossible for Guardiola’s side.
Speaking to TNT Sports after the game, Haaland didn’t hold back in his assessment of the ‘embarrassing’ loss.
“I take full responsibility together with Rodri, Gigio (Donnarumma), Tijjani (Reijnders) - us experienced players.
“I don’t want to blame anyone but we need to take more responsibility, because at the end it’s not good enough. We’re Man City, we can’t go around and not win games, it shouldn’t be like this.
“I don’t have the answers. I take full responsibility of not being able to score. I just apologise to everyone; every single Man City supporter, every supporter that travelled, because in the end it’s embarrassing.
"Honestly, I don’t know what to say because I don’t have the answers, and what I can say is sorry.”