Yes you would def. risk getting points & fine regardless of how the damage occurred. The only thing to do is to check tyres straight off the rollers. Agree predominately steer tyres though sometimes on trailer too - am no expert but suspect higher load per tyre in those positions requires more braking effort to pass and therefore creates more sheer force in the tread area. In my experience if you check down below the rollers you will find numerous pieces of tread rubber. You may even find the pieces that have come out of your tyres. If it can be proven that the damage happened on test, VOSA have a system where they will pay for the tyres to be repaired.