Did they have neighbors close by? I can’t imagine neighbors not questioning what was happening if they were close enough to see. We don’t leave town without letting our neighbors know and we don’t leave lights that would advertise that we’re not home. Even the timers tell a different story to folks perhaps casing a home. I read until a different hour every night so having the lights go off at a set time is a sure bet they are on a timer.
A couple of weeks ago we had a friend come in and feed and medicate our cat while we were gone for three days. She decided on her own to turn on lights because it was TOO DARK for the cat. This immediately told anyone up to no good that no one was home - lights on all night???? The “I was just trying to help” kind of friend. She’s done the same with our thermostat before - we set it where we want it when we leave and she for some reason can’t resist meddling with it. Won’t happen again!!!
Coming home to find that you have to have everything you own taken out of your house is almost as bad as finding it already gone.