Has person-to-person transmission been proven for H5N1? It's still quite likely they were both infected from the same animal. If they can prove spread between people, that's a big problem... Until then this isn't a risk, other than the major implications for agriculture and food supply.
As far as I've read, they aren't sure about human to human transmission. Roughly a dozen people have had H5N1, but they all plausibly could have gotten it from poultry handling. Which means a) no need to panic, but definitely a good idea to keep an eye on things in case we do observe human human transmission and b) Maybe we need to revisit how we raise animals for food....
Maybe the problem isn't how, but how many.