Well, I don't want to dable into the technicalities of this whole sending bitcoin to the wrong address and the possibilities of possibly getting those bitcoins back, because I am not too knowledgeable when it comes to the technical side of bitcoin.
One thing I've always believe is that, if one mistakenly sends bitcoin to the wrong address, whether someone somewhere got the funds or not, the fact remains that those bitcoins are lost, and the possibilities of getting it back is as good or bad as zero.
The only way the sender can get that money back is if the person that received it is a good Samaritan and decided to send the funds back to the same address it came is came from, though the chances of this happening is always very low due to the anonymity with cryptocurrencies, that is, transactions can't be traced to a particular person except on occasions some people make their bitcoin address public.
So, the best advice is, avoid making the mistake of sending bitcoin to a wrong address, whether someone receives it or not, a loss is always a loss.