Hi,
When you do your lookup for the technician, there are multiple target records created from one source record (so you get an explosion of data records when you load from source to target).
The result package has a unique technical key of DATAPACKID and RECORD.
In your example there are 4 result package records with DATAPACKID = 1 and RECORD = 542, so the result package records are not unique and that's why you get the error.
Please check SAP Note 1223532 (Desgin rules: Adding records to end routine). It describes how to solve this problem.
Rgds,
René