Neighbours don't you just love them, how fortunate us boating folk are that if we don't like them we can untie and moor elsewhere, take pity on the bricks and mortar folk who cant. Give your neighbour a break, there could have been a plausible reason as to why they needed to do their washing. surely the engine was not that loud?
Us boating people need to stick together, bickering over an engine running seems silly.
If you were going to bed then I could understand it,
We have a neighbour with a very loud friend and when they sit outside you can hear her screeching voice above everyone else's, no problem to shut out the irritation just close our doors until she has gone :-)