speaking on the other side of the fence,
i purposely avoid asking trade neighbours to do jobs, i don't like the thought they might think i'm asking them to get a decent price, also if anything goes wrong i've got to live next to/ up the road from, not only that invariably when i'm doing things its the weekend and its also their weekend if i'm knocking on the door for favours they arent really getting a weekend as it's their day job id be asking them for help with.
i'm lucky i can do 90% of stuff myself and only get trades in for things i cant do (like the boiler).
however there is an exception, there is a kitchen fitter over the road, my wife gets on with his wife and our boys get on well, so i've asked when the time comes if he can be the middle man so we can get a kitchen from howdens and we'll bung him a few bob ontop for his time.
also i used to have a friend who's dad owned a garage, he always used to say why dont you get me to do your cars (i do 99%, but sometimes i just dont have time to do it so take it in), my answer was always "i dont want you to think i want special prices / treatment, and should anything go wrong i dont want to have a falling out over it", he never used to understand it.
on the note of "if" something goes wrong, and i'm not naive enough to think that nothing goes wrong, if you get a neighbour or friend to do it, the assumption would always be they are doing it as a favour so if it goes wrong it they would expect me to pick up the bill because they are doing it as a "favour".