Tesla is open source, and literally sends tech to other companies (Ford) in the hopes of advancing EVs... Masimo smirks and throws up the money sign, ala Johnny Manziel. Disgusting.
Tesla's "open source" pledge comes with significant strings attached and adhering to it basically means invalidating one's own patent portfolio.
Furthermore, patents are not the only way to protect an invention, the other most prominent being trade secrets which Tesla definitely makes significant use of.