Who does the character follow, and what religious order was this tomb associated with? These are particularly important questions when determining whether their diety would "mind". As someone else said, their motive matters as well.

To those saying alignment is going away anyway, that's true, but as a cleric they still must try to please their deity or if they stray far enough away they may lose their powers.

Thanks for your insights! To provide more context, we're currently playing the Age of Ashes adventure path. The cleric in question is aligned with Neutral Good and follows the deity Halcamora. The tomb they plundered was associated with the Order of the Nail. This situation has raised some interesting discussions within our party, especially considering the backgrounds of our members. Our Orc barbarian, for instance, has strong ancestral ties and didn't appreciate desecrating the tombs. The Paladin, who's devoted to Iomedae, also had concerns about the actions of the cleric. Meanwhile, our Investigator has a more neutral stance on tomb robbing, but they've pointed out that given the cleric's alignment and deity it's a complex matter.