those who have settled with gas companies following a spill or other accident are forbidden to disclose information to investigators.

I guess it's worth to re-post this on-topic story from last week here:

Children given lifelong ban on talking about fracking | Environment | The Guardian

Two young children in Pennsylvania were banned from talking about fracking for the rest of their lives under a gag order imposed under a settlement reached by their parents with a leading oil and gas company.

The sweeping gag order was imposed under a $750,000 settlement between the Hallowich family and Range Resources Corp, a leading oil and gas driller. It provoked outrage on Monday among environmental campaigners and free speech advocates.

The settlement, reached in 2011 but unsealed only last week, barred the Hallowichs' son and daughter, who were then aged 10 and seven, from ever discussing fracking or the Marcellus Shale, a leading producer in America's shale gas boom.