Well they've had 6 years & 12 million squids to expend, I'm pretty sure they would have noticed these inconsistencies by now & they'd have ironed all that out when they questioned Kate & Gerry.
When did that happen again?
You, like the rest of us, haven't the foggiest idea about who was interviewed and who wasn't.
When did they interview "innocent dad"? When did they interview the victims who were assaulted as children by an intruder in their bedrooms when they were on holiday in the Algarve? When did they interview anyone as they went about their cold case review of missing Madeleine McCann?
In my opinion they most certainly carried out interviews in the run up to Madeleine's case being reopened because they had to have the evidence which justified that.
How else do you think they gathered evidence if witnesses weren't interviewed?
Just because these interviews were not in the public domain does not mean they did not happen.