Police officers are not witnesses to the accident - they rely on the physical evidence, witness statements, and the statements of the persons involved to form their opinions about who caused the accident. There are many circumstances that preclude moving the vehicles, such as driver injuries and vehicle damage. When there is no physical evidence of where the crash occurred and you move your vehicle, the responsible party that caused the accident, or their insurance company, may take advantage of this situation and blame you for causing the accident.
If you are able to safely move your vehicle off the road, out of harm's way, generally you should consider safety first for all concerned. This is yet another reason you should have experienced legal counsel to represent your interests in explaining your conduct to the insurance company.