Disposition review, error message for the reviewers

As per the Microsoft documentation https://learn.microsoft.com/en-us/purview/disposition, I gave an user the 2 necessary roles : Data Classification Content Viewer and Disposition Management. When the disposition was triggered, the user received an email and could click on the link 'Disposition Page'. He can then see all the files that need to be reviewed however when he tries to view the content of the files, he gets 'Error: Access denied'.

This user didn't have access to those files in SharePoint: it was a test. When I gave him read access, he was able to preview the files on the Disposition Page.

I don't see in the documentation that it is necessary to give the reviewer access to the content. Do you experience the same behaviour?