Masimo Corp.'s "empty voting" claims against ousted founder Joe Kiani are a pretext for rejecting his $450 million severance demand after Politan Capital Management LP seized board control, according to an investment firm involved in the court fight.

RTW Investments LP moved to exit a federal securities lawsuit brought by the health technology company, one of several cases spawned by the proxy battle. Kiani and his ex-company -- now directed by the hedge fund's former board nominees -- are also locked in parallel litigation over the severance payment in Delaware and California.

The empty voting claim is "a public relations stunt" dreamed up by ...