Use that description as a starting point to identify which records to gather, but base the filing on the employee's own training history, project documentation, and any written work product that supports the claim.
Move from a secondhand account to primary records
Request the specific project files, training certificates, or internal documentation the colleague's account points to, and confirm dates and the employee's actual role in each. A secondhand description helps focus the search but should not appear as the only supporting evidence.
The company's own validated process files, revision histories, validation reports and deviation investigations naming the specialist, alongside training materials the specialist produced. Provide the table of contents of the internal manual, sample pages of the schedule library with commercially sensitive values obscured, the calibration procedure written for the group's own sensors, and the internal defect taxonomy. Quality records often contain product, customer, or regulatory detail that should not leave the organisation, so agree with the quality lead who approves the extracts and keep an index of what was withheld and why.