Last night's errant goat made it back to his side of the fence just fine. We found him and his goat friends again this afternoon, some of them on our side of the fence. Dad went all shoo-ing and "Go on" at them, and they went through a weak spot in the wire-mesh fence back on their side, so Dad knows another weak spot he can reinforce.
Dad added that he wouldn't mind the goats coming over occasionally for weed control. He's talking with the owners about putting in a gate so that the goats can be herded (key difference to them just sneaking through the fence) over there for special eating, while we watch and make sure they don't eat the landscaping...or, for that matter, the fence. They have stomachs like sharks, I tell you.
I'm back home in Portland now. If I run into goats here, I'll be mighty surprised.