A YouTuber wrecked his Tesla Plaid (a super-fast model) by modifying the brakes but failing to upgrade the brake fluid. The high temperatures achieved by braking at 170 mph boiled the fluid, and he lost control of the car. Lucky to be alive, the YouTuber is probably SOL with his insurance company.
While the driver was wearing a seat belt, he did not have a helmet on. He also did not have track-specific seats or a five-point harness. He suffered a fractured knee, a torn ACL, and five broken ribs, but survived the impact.
As Chet stresses, the new brake components were not the source of the problem. In a previous video documenting the brake change, he mentioned that he was moving to new calipers and carbon ceramic discs in the front, plus racing pads on new iron discs in the rear. He also added a steel-braided brake line to the front, but not the rear.
He did not, however, switch away from DOT3 brake fluid. Regular track drivers wisely upgrade to a more track-friendly fluid such as DOT4 (or higher, depending on what else they change in the braking system) that safely operates at higher temps along with any upgrades on pads, rotors, or whatever else. Chet says he will clarify the specifics of the failure in a yet-unreleased video, but his comment on the original video suggest that the lower boiling point of the lower-grade brake fluid caused the crash. That led to the worst-case scenario, with brakes failing near top speed on a 4800 lb sedan.