I'm not seeing the "widely enough" in this case. Finding life on the one moon in the solar system that could support it, specifically finding life that is organic, would very much suggest single origin. The original Hanson paper sounded almost like it was actively avoiding that possibility. Thus my impulse to state it more strongly than is strictly necessary. Finding life close to us may increase P(panspermic hypothesis), but it increases P(common origin) more, and this ratio diminishes as we find life further and further away.