They couldn’t see, if they could they would’ve seen her being taken.
It’s not as if they would’ve been constantly looking towards the complex without taking their eyes off the apartment - they were eating, drinking and socialising with their group of friends. They weren’t doing a stakeout.
If you believe someone took her you have to admit just being able “to see” part of the apartment (one of the unlocked doors was on the opposite side of the apartment - they definitely could not see that door and that’s also admitted on the documentary) wasn’t good enough because someone went in (1 missed sighting) and came back out with Madeline (2 missed sightings). They didn’t even see 1 of 2 the sightings and missed 2 potential opportunities when they could’ve seen and done something.
They couldn’t see the road or the window to the room - which was climbed through to take the child.
I’m not disputing any of that. I’m disputing that they could see the apartment from where they were sat.