A worker won $600,000 after Twitter said his goodbye messages showed he had resigned. The case holds valuable lessons for staff and employers.

• A former Twitter employee in Ireland won about $600,000 for unfair dismissal.
• Twitter assumed his resignation after he didn't respond to an email telling workers to commit to a "hardcore" culture — or quit.
• HR and legal experts told BI what lessons the case holds about communicating with your employer.

Gary Rooney had worked at Twitter for nearly a decade.

He was director of "source to pay," a procurement role, in Twitter's European headquarters in Dublin when Elon Musk acquired the social media platform for $44 billion in October 2022.