I once had to ring the police around 30 years ago. I looked up the local station as it was a local incident and I never thought for a second to ring 999
Putting myself in Jeremy's situation at the same young age he was, I honestly would have dithered, telephoned someone I knew, dithered a bit more then rung the local cop shop and gone very slowly to the farm in the hope the police got there first as I would have been scared and a bit of a ninny. If you are of the viewpoint that he is innocent all his actions seem quite natural to me.