I read some interesting research which found that people fall into one of two categories - askers and hinters, or similar. Sorry to be vague, but I don't remember the detail, but the gist is as I've said.
Basically, askers do just that - if they want something, they don't beat about the bush, but come out and say so. They don't like hints, as they find them confusing, and are not good at recognising them anyway. Crucially, though, they are not upset if you say no when they ask for something.
Hinters do not ask directly, in case it causes embarrassment. Instead, they drop hints, let people know indirectly that they want something, and tend to get upset if they don't do it. They don't get upset when others hint, and are good at picking up on cues.
This would all work swimmingly, until you get a hinter and an asker in a relationship of some sort, and each drives the other insane. The hinter thinks the asker is impossibly rude, and the asker gets frustrated with that they see as passive aggression. Both expect the other group to behave as they themselves do, as to them, that is 'normal', and get upset or offended when they don't.
I wonder if you are a hinter, who expected your neighbours to help you out, and they are askers, who assumed that you would have asked if you did, so you must have been ok. Their asking you will seem to them normal, as that is just what askers do. Neither of you is being unreasonable or a bad neighbour. It may just be that you have different styles. Is that a possibility, do you think?