I'm feeling a bit pissed off but maybe unjustly...our toddler managed to throw a ball off the balcony, and it bounced off and went into next door's garden. It was there for about a day, still there this morning, and I assumed they would throw it back - we could have asked for it but I didn't like to bother them - but when we went into the garden this afternoon they told ds1 that their dog had attacked it and it was no more.
If their son's ball had come over into our garden, and one of our pets had destroyed it I would offer to replace it. But maybe I'm being daft?
Ds3 just woke up crying about his ball, it was his favourite and he is only 2 
We have got him two more similar ones but I just thought it was a bit unkind to leave it there till their dog got it then not even really give a stuff.
They seem like very nice people normally. Maybe they are pissed off that it went over but our balls very rarely do as I don't let the older ones play with them in the garden for this very reason.