Jesus H Christ we’ve been through all this a million times. If I was still a mod I’d be pm’ing you with a warning about trolling so it’s probably a good job I’m not.
The window was open because Kate opened it from the inside. They claimed it’d been forced open from the outside but it was proven conclusively by forensics that it hadn’t been.
They were desperate to paint a picture that a third-party had somehow got in. Gerry first claimed he’d gone in through the front door, using the key. But once the forced window story was proven to be false, he admitted the patio door had been unlocked. It couldn’t be locked from the outside so had to be left unlocked if anyone went out. You can speculate whether that was because they were initially frightened about being accused of negligence or because they were desperate to divert attention from something more sinister.
It doesn’t matter in one sense what the reason was as, one way or another, they lied to the police and potentially obstructed an in-progress criminal investigation. Should have been done for that alone but that probably wouldn’t have helped anyone.
It’s an inescapable fact that the false trail they seemingly tried to lay once it was known that Maddy was missing renders them liable to the deepest suspicion. All their actions were seemingly designed for the express purpose of covering their own arses rather than finding their child and, for that reason, I find it hard to believe that they don’t have some knowledge of what really happened that night.