It's highly possible that a long list of queries would emerge if SY only had the same witness statements as we have to go on.
However the idea that they would not use their ability to contact the actual witnesses themselves for clarification but instead would behave as we - (who don't have that ability to make checks with the folk concerned ) do - is crackers IMO.
I gave reasons why investigators may not always confront witnesses. My opinion is as valid as your opinion that they trot back and forth every time they want clarification of a point. No wonder they needed such a lot of staff if that's how they work lol.
The statements made to the first investigation are there for all to see and read. The idea that a different translator can 'correct' them is crackers imo. OG can ask the witness anything they like but four years after the event it's unlikely that anything new or useful can be remembered.
In this way, at about 21.05 the witness came to the Club, entered the room using his respective key, the door being locked...At about 22.00 it was his wife Kate who went to check on the children. She entered the apartment by the door using the key...
http://www.mccannpjfiles.co.uk/PJ/GERRY-MCCANN.htmDespite what he said in his previous statements, he states now and with certainty, that he left with KATE by the rear door which he consequently closed but did not lock given that that is only possible from the inside. Referring to the front door, while he is certain that it was closed it is unlikely that it was locked as [because] they had left by the rear door.....
He followed the normal route up to the rear door, which being open he only had to move [slide] it, that being the way in which he entered [was entering] the lounge,
http://www.mccannpjfiles.co.uk/PJ/GERRY-MCCANN-10MAY.htm