HE was standing on the lawn of a neighbor of Georges. GZ knew he did not belong there. HE knew he did not live there yet there he was on a rainy night, Standing on his friends property. That is suspicious. It would be to me if I looked out and say someone standing on my neighbors lawn that did not belong there.
There were also recent break ins. It makes sense.
I understand he was cutting through the neighborhood walking under buildings "overhangs" to keep the rain off him.