That is one tough situation! I Think I would drive the fence line and see if what he says is true. If it is true I would take plenty of pics. I would take a good witness or two also! Most people of this caliber will not take care of the bate animal (feed and water) so go every day and take pics. If he does not tend to the hog in the trap or cage looks to me like your local game warden could help you out. Just remember a picture is worth a thousand words!