No, the AG said the checks weren't as regular as stated, that does not mean that he says they "lied". Nobody is accusing Mrs. Fenn of "lying" for example, but most people know it's impossible to determine exactly where a sound originates from in apartment blocks like those the McCann stayed in while in PDL.
This is what the AG says about Mrs Fenn :
'Pamela Fenn, who resides on the residential block's first floor, above the apartment that was occupied by the McCann family, clarified that on the 1st of May 2007, two days before her disappearance, at around 10.30 p.m., she heard a child crying, which from the sound would be MADELEINE and that she cried for an hour and fifteen minutes, until her parents arrived, at around 11.57 p.m.
This shows that the parents were not persistently worried about their children [and] that they didn't check on them like they afterwards declared they did'
So it is Mrs Fenn's evidence that lead the AG to believe that the McCanns were being less than truthful about the regularity of their checks. They say they checked every half an hour, Mrs Fenn, who the AG seems to find a very credible witness, suggests on the night of the 1st of May the children were not checked for over an hour. So for those who suggest that the AG did not imply that the McCanns lied are simply wrong. He most certainly did and the weight he bestows on Mrs Fenn's evidence clearly shows this.