He was completely overwhelmed the entire tournament, bad turnovers/giveaways, getting caught out of position, getting caught in his own zone endless times. Poor gap control, poor defensive reaction, just an all around bad WJCs showing from all 5 games that I watched.
Johansson had a few brainfarts too, but I thought it was really frustrating having Soderstrom as his primary D partner 5v5, and many times their shifts were too much time defending instead of creating offense because of mistakes Soderstrom had created that led to the other teams getting possession.
People can criticize Broberg for his WJCs all they want, and I thought yeah, he had a rough tournament. But I do think Soderstrom's poor tournament was a bigger factor in Sweden underacheiving than Broberg was.