Electronic Signature Checklist Task showing incorrect details

We have implemented electronic signature to a checklist task which on the whole is working as expected however in certain situations the document when being generated is displaying details of a different colleague.

The data model is setup correctly with the required parameters and works fine where a colleague doesn't have a system role that allows them to view other colleagues (i.e pending worker role). However if a colleague has a role that allows them to view other colleagues details in the system it then generates a document based off a random colleague's details (that they are able to see as part of their security profile). The data model even has security tables applied so not sure how this can happen.