I think domestication,would have happened many many times,and stealing pups,banished individuals living alone scavenging,and the odd 'friendly' wolf would have contributed to the process along with matings with different types of wolf , and coyotes ,as well as dogs from different areas,
As saluki 246 said above some wolf packs even now allow people fairly close,coupled with humans feeding them,the odd thrown bone etc you can imagine a some within a few generations
Learning to trust humans.then when pups were about, being imprinted .if you look at the Iranian wolf it's very simular to pres