I'd be shocked if Rawlinson's compensation package didn't include a hefty non-compete inducement of some fashion.
Courts are becoming increasingly hostile to such agreements, and California is one of the states that now bans non-compete clauses in employment contracts, even for employers based outside the state. However, there are other ways to structure an inducement not to compete if done cleverly enough.
Keep in mind, too, that all the significant engineering breakthroughs Rawlinson brought to Lucid are covered by patents that are owned by the company. It would be Rawlinson's general engineering talent and creativity that would be a competitive threat, not anything specific he knows about Lucid technology. And now 68 years old, wealthy, and coming off some intensely grueling years at Lucid that have left him markedly aged, he may just be ready to move on to another phase of life.