According to Gerry's sister on 4th May;
"Kate went back at 10pm to check, the front door was lying open, the window had been tampered with, the shutters had been jammied open, and Madeleine was missing."
http://www.gerrymccannsblogs.co.uk/press/1may7/04-05-07-Times-Transcript.htm
I assume she was repeating what she had been told at 23.40 when her brother phoned her. Her account differs from that of Kate's parents as they mentioned the broken shutters but not the open front door. They were called just after midnight.
So did Gerry and some others know something that Kate didn't? I tend to think they did and this following is my reasoning:
1. Gerry told Kate to commence her check (urgency)
2. She only took a couple of minutes to do her check, yet it seemed like 10 minutes to Gerry (anxious to know the outcome)
3. The guys started looking for Madeleine in the immediate vicinity without checking the actual scene first (no need for a plan to be formulated based on evidence).
4. Fiona was asked to stay there in case Madeline came back there, not in case she wandered but actually wander back there (seems somewhat based on knowledge).
I feel that Mark Rowley had been told about these circumstances earlier as he said in 2017 "however Madeleine left the apartment, she was abducted" So that to me is him saying "let's not get too fussed over the reason why she left the apartment, we know she got outside for some reason, and hence because she wasn't found immediately she must have been abducted."