IIRC, the companies that stopped advertising with Twitter had asked about whether Elon would handle the Trust & Safety team correctly at a conference right when Elon was preparing to take over as CEO.

The official response was to dodge the question.

Not only can Elon pin blame on the research agency for his own explicit actions, he can't pin blame on the research agency for an exodus that started before the research agency released its findings. It would be like breaking your foot, going on a rollercoaster with a broken foot, and then suing the theme park for breaking your foot. I'm not a lawyer, but in any sane court, that wouldn't hold water.