I have no connection with DSP, and no reason whatever to believe it is anything other than an entirely professional TV production company.
However, writing as someone who once appeared in an aviation programme by a different company and wishes he hadn’t, may I respectfully suggest that anyone intending to co-operate in a future programme about the Comet, or any other aviation topic by any production company, first ask a few hard questions to establish that there is a genuine interest in facts, and an ability to deal with the complexity of issues arising rather than a desire to add to the sensationalism and misinformation that so often attaches to subjects like this, before getting involved.