How did an unreturned laptop lead to Apple suing its former close partner OpenAI?

In its lawsuit against OpenAI for trade secret theft, Apple claimed that its ex-employee, Chang Liu, stole a company-issued work laptop after quitting to join OpenAI. Liu continued to access confidential hardware-related files using a previously unknown authentication bug while working at OpenAI, Apple claimed. The iPhone maker then investigated Liu's messages, which eventually led to the lawsuit.