It doesn't strike me as paranoia. Thinking that industrial espionage doesn't happen seems naive.

What they have is an admitted saboteur and code that exports data to third parties. It quacks like a duck. A disgruntled employee succumbed to or sought out people who wished to do harm to Tesla.

There's plenty of evidence of similar things happening. (edit to fix words)

If you work in the defense industry you get things like this drilled into you as regular required training. It's not paranoia, it happens regularly.

He's a bit odd in how he addresses the problem, and calling out potential threats was perhaps an unusual choice, but not unwarranted.

American companies have overthrown governments to benefit their business, stealing secrets and sabotaging a competitor isn't exactly out of the ordinary.