Jessie J: Domino theory

The lawsuit in which Loomis And The Lust's claim that their Bright Red Chords sounds like Jessie J's Domino is same-old, same-old, until you get to this bit of the MTV report:

In April, Loomis uploaded a video of the band's song with Jessie's vocals laid on it, but the clip has since been removed on "copyright grounds." However, a music video for "Bright Red Chords" remains online, allowing fans to determine if Loomis has a case against the British songstress.

I know there could be a fair use argument for a stretch of the vocals being used, but isn't it undermining your own case to a 'being left open to a counteraction' extent to steal the vocals of somebody you're accusing of stealing your melody? It's a bit like breaking in to someone's house to see if you can find the things they pinched when they broke into yours, isn't it?