One more update - the neighbor (who is on a cruise right now) was very apologetic, but my wife was like, "Do you know my husband? He loves cats." Our neighbor does know me, but she may not have realized that our cats are really mine, and I'm the one that brought a cat into the relationship. Tubby wandered into probably the best possible garage, from that point of view.
I do hope she comes back to visit, ideally without getting trapped this time. I haven't seen her since just after the picture above. Maybe we should install a one way cat door - let them out, but not back in, if that's a thing.

