Investors had mixed reactions when Rivian Automotive (RIVN -6.35%) reported third-quarter results last week. The financial results were disappointing, with lower revenue and a higher reported loss than expected. But the electric vehicle (EV) start-up reaffirmed its delivery expectations for the full year, even though supply chain issues have recently impacted production and its finances.After digesting this latest news, one Wall Street analyst felt the mixed results still meant investors would do well to bu ...