You did the right thing but I would pass copies of the tape to the father of the two trespassing sons and then try once again for permission to recover a killed animal on his land. If says no them inform him you are taking the tapes to the local authorities with the entire story. I know that they will be very supportive of you since you took the high road and I'm sure that they would take a trip to your neighbour's property to warn them of future trespassing charges. It is at all time better to be the better human being and not the lesser as well as it will provide an excellent example for your son.