It's the Dresden multiverse. In one verse Carlos Ramirez is Harry's secret ally. In another Carlos Ramirez no longer trusts Harry. 
If the emoji doesn't tell you, I absolutely hate this idea. Please consider the above to be a bad joke. If it turned out to be the correct explanation I would be greatly disappointed. It would allow Jim to do almost anything with his characters, with little rhyme or reason for changes in their behavior from one novel to another. Worse, the remaining novels in the series should be setting up the finale. If major supporting character's behavior becomes erratic, it could, probably would make this setting up phase less coherent and the reading far less enjoyable.
Exactly, why the change in attitude when Carlos first shows up at the castle? Nothing in-between, if they met by chance, or if Carlos took Harry aside or it that last meeting in Battle Ground hadn't been so absolute! Why is Harry so trusting of Carlos all of a sudden after Carlos really stabbed him in the back and kicked him when he was down at the end of Battle Ground?
It seems the most obvious reasoning. Harry sends Toot out to alert people. Harry isn't at all surprised that Carlos shows up.
But Toot doesn't know that Carlos is team Harry now does he? Odd don't you think that Carlos is there minus his cloak and says he isn't there. That smacks of pre-planning.