OP, I have only read your post and no replies yet, so if I am repeating anything, sorry. Let me start with saying that I have been a cat owner for over 30 years. I am adamant about cats being indoor only to the point of being preachy to some of my neighbors about their allowing their cats to roam. I also am part of a feral rescue group. I have fed, trapped and fixed so many cats over the years I have lost count (but I remember each one). I have had to bottle feed litters because their moms were killed, I have seen cats die from antifreeze poisoning (heart wrenching), I have managed to turn some ferals into sweet house cats, I have been out in wicked snow storms and below zero temperatures making sure all of them could get to the houses we make and right now in my basement is a momma feral and her 2 almost 2 week babies that I am taking care of...there was 7 kittens but due to an idiot not waiting for me to remove them from the spot she had her babies (that wasn't bothering anyone but this idiot who thought the kittens should be killed) and having someone take them at 2 days old for a time before we could get them back and trap mom(10 hrs), we lost 5 of them. I have seen cats maimed and killed from them hiding up under cars, I have seen people purposely try to kill them, I have seen them hit by cars, mauled by other animals. Most of these cats had been someones pet. They thought "well kitty loves to be outside." Yes, cats love going outside (*disclaimer...I have an escape artist too, but she runs out, hits the porch, then panics and wants back in), but the dangers for them are too great. Your neighbor obviously has an issue, be it true or not with your cat roaming, and is already making complaints. You love Sam, let this be a wake up when someone is making threats to do something that it is time for Sam to learn to stay in. If your neighbor calls animal control, they can pick the cat up and depending on your town, sometimes these animal control places only have 24-48 hr hold before they euthanize. It is a very big sore spot for me on that, and we just got one place successfully closed due to this, but it is a fact. Some tips are indoor cat grass gardens, squirt bottles when he makes a run at the door , continue the walks on the harness if you want, building an enclosure in your yard where he can be out but he is safe, and please make sure he is chipped. His safety comes first.