Assume they don't give a s*it or it could be they haven't noticed it falling off the trailerThere is a grain slick on the road just along from here, on a bend just ready to kill a motor cyclist, caused by overfull trailer pulling out. Would gave been fairly easy to brush it into gutter. Have to assume some don't give a s**it, and leave it to public liability insurance.
There is no excuse, sorry to OP for your troubles. If you have a genuine case, ask your insurers to seek compensation from landowner involved.