No, but he had access to a bike and his two legs. The horse element doesn't come into it - as far as I know, the farm only grew crops - no animals!!
How do you know he didn't have access to a horse? I find it difficult to believe in all those fields farmed by the Bambers or in neighbouring fields there wasn't a horse? There's a difference between a farm having a horse or horses (I have 2 but no farm) for recreational purposes and livestock.
Anyway I think the farm did have some livestock.
Are you the only one allowed to come up with new theories eg the trailer?
Was the sighting of a scruffy hunched up man running away actually a scruffy hunched up man or a horse?
Did MM have access to a horse? Did Jeremy tell Julie how MM arrived and departed the farm?