If they signed something to say they read something and agreed with it and hadn't, that is lying. A certain PJ policemen was convicted of the same.
Of course in the real world they were read an officially translated version of it so could sign it truthfully.
I'm assuming that ''Reads, ratifies and signs'' was also typed in Portuguese - and so not necessarily understood at the time of signing?
After hours of interrogation - with every word having to be translated and retranslated- and with every question and answer having to be typed up by the PJ officer - it's not rocket science IMO to assume that all involved were pretty tired by the end of the session.
There is a vast difference between listening to a long statement being read out to you by someone else at THEIR pace, and probably with a foreign accent - and reading a statement, written in your own language and at YOUR pace - when written mistakes would be far more easier to spot.
I have no doubt that mistakes were made - but no-one is to blame for that IMO. There is no such thing as a perfect human being - no matter what their profession is.
AIMHO