Nothing wrong with dog Imo, he was more than likely trying to tell you something, didnt like the bloke and he showed it. Big bag of toilet roll is something different thats made him unsure, protecting car is normal. Showing an instant dislike to someone for no apparent reason and id be inclined to think the bloke were dodgy and dog knew it. Bit of advice for anyone on here, any strangers start showing alot of intrest in your dog asking questions and wanting to come round see him, best thing you can do is tell them to feck off or tell them some bull shit, dogs shit, terminal illness, infertile,