Interesting. I wonder why, if the radar station was only to be operated until 7am, they were ordered to shut it down at 6:45am? On the day there just happened to be an invasion force on the way to be in detection range at, as it turned out, 7:02am. Unless it was normal to cut out early it seems an odd coincidence.
My strong impression is that radar was still a bit of a novelty, and wasn’t taken especially seriously or depended on then. More telling to me is the maritime reconnaissance capability that was present and not used.
Pearl Harbor hadn’t happened yet. Complacency bias is nothing new, and I think that was most of what happened.