the Instructor Form 1 asks for a Test Report Form
It does indeed, but if you read the Guidance Notes on the SRG 1169 page i it says:
Only Instructor Form 1,2 or 3 as appropriate should be sent to Aviation House. The Examiners Record replaces FCL685 and must be retained by the FIE for a minimum of 3 years.
If the CAA want it they will ask the FIE who should not have given it to you.