With his well-known gift for overstatement, 'American Idol' critic Simon Cowell called Irish favorite Siobhan Magnus' performance 'manslaughter' last night. That's another of his famous over the top assessments,  but the truth is she did hit a number of dud notes.

The season nine leader genuinely struggled through Chaka Khan’s "Through The Fire" at the start of the two-hour live show, raising eyebrows during a number that seemed tailor made to her talents. She looked nervous and uncomfortable and later admitted as much.

This week’s R&B and Soul theme should have played right into her hands with the style of singing Magnus has said she enjoys. Instead the 20-year-old seemed to struggle with Khan’s 1985 ballad leaving Cowell visibly unimpressed. But a bad night for Magnus doesn't help the the other contestants’ in their attempt's to topple her throne.

Magnus’ main competition, Crystal Bowersox, got behind the piano for Midnight Train to Georgia last night. The Ohio belter proved once again she an artist of another category altogether. In fact she's prompted many to openly wonder what she's doing on Idol in the first place?

Meanwhile it seems fair to say that R&B singing is not where Siobhan Magnus will make her money. The judges were quick to pick on her, with Ellen DeGeneres saying that it was not her best performance, and Randy Jackson saying: “I don’t know if it quite caught on pitch-wise.”