Which significant labor relations case dealt with unionized employees' rights to have representation during investigative interviews?

The case that addressed the rights of unionized employees to have representation during investigative interviews is indeed NLRB v. Weingarten. In this landmark decision, the National Labor Relations Board (NLRB) established that employees covered by a union contract have the right to request union representation when they are being questioned in a way that could lead to disciplinary action.

This ruling is significant because it reinforces the principle of fair treatment in the workplace and recognizes the role of union representatives in ensuring that employees' rights are respected during potentially intimidating situations such as disciplinary interviews. The case highlights the importance of allowing employees to have someone with them who can provide support, clarify their rights, and assist in navigating challenging discussions with management.

The other cases mentioned do not address this specific issue regarding representation during investigative interviews. Their focus differs, which helps to delineate the unique impact of the Weingarten decision on labor relations.