It appears that Mark's neighbor can see into 2 windows on the side of his duplex facing her. However, an exterior shot shows high hedges growing between the two buildings and covering any lower level windows.
At 53:32, a paramedic calls out, "Whoa! Whoa, whoa, whoa, he's down, he's down!" prematurely, about 4 seconds before a character collapses to the ground.