It's indirect speach, yes. But are you suggesting the accredited interpret mistook "shut" (fechado) for "open" (aberto) ?
I remind you that Mrs McCann had to sign the statement after having heard it retranslated in English. There's no syntax issue here, just the simple word "open", repeated 3 times. Without Mrs McCann noticing ? Come on !
I'm saying that where the opening and closing of three different items i.e. windows, shutters and curtains is being discussed in the same conversation - the language barrier would be a reason for small misunderstandings to occur over what was open and what was shut and when.
It may be that Kate didn't notice a small discrepancy when it was being read back to her. There is a huge difference between having something read back to you at the readers pace, and actually reading words on a page at your own pace where discrepancies would leap out of the page at you. Having to have everything translated and re-translated back and forth during interviews which could go on for many hours must be very tiring, so once again there is room for human error on both sides due to fatigue.
There are 3 statements. Two by Kate herself in her own words so we know there is no possibility of error there. and one statement which is a summarised interpretation by someone else of her words - where IMO there is room for error.
And of course at the time Kate had no idea that every single word she ever spoke was going to be pored over, put under a microscope and dissected at some future time by people looking to find fault.