"Tesla lawyers argue Musk cannot be held accountable for public statements [about car safety] because anyone could have made a deepfake of Musk, so no public statements can be taken seriously." Court laughs.
He can't say "because I'm the target of deep fakes, you can't use any video evidence against me".
Photoshop, videos with doubles, and other such impersonation issues have been a thing for a long time, and the courts have found ways to deal with them.
What you say matters. A lot.