Some bees are no joke. Years ago my mom was mowing the grass trying to get in “better health” and she hit a pile of old wood (cut logs) for the fireplace then got swarmed by a number of bees which stung the hell out of her. I came out since she was screaming and sprayed her with the garden hose which seemed to slow them down / get them off of her so she could get in the house, some did get in the house though.
There wasn’t nearly as many bees as shown in the photos above, but they were vicious suckers!
They were all around me but I didn’t get stung at all, they completely left me alone. Funny enough, my dad got home from work and my mom told him about it, he went out to “take a look” with a big stick in hand, then got stung bad enough he had to go to the hospital, lol, I couldn’t believe the stupidity of going over there with a stick after being told how bad it was and NOT to; he probably did it because he was “told not to”, you tell him to put a seat belt on as no one can afford a ticket and he won’t.
I sprayed the crap out of the hollowed log they had their hive in with bee / wasp killer spray late one evening then burned the sucker in the fireplace; that took care of that problem. I never got stung at all which was surprising. Some can be relentless!
I’d be forcing your neighbor to get a pro out to deal with that for sure…