The entire cast has their moments of nastiness and moments of perfection, and this is just one more scene following in that vein.

I'd like to point out that in terms of the "detective work", this is a recurring element in the series: solutions appearing out of thin air after dangling the plot thread in front of our nose, sometimes for multiple books). For example The Cleansing - the solution came out of nowhere, Who killed Adeleas - solution literally presented herself and the thread was over in two or three lines of dialogue, remember earlier in the series, when Moiraine didn't know who the Dragon Reborn was out of the three boys? Well we found out by the end of the book and not in a subtle way, either (the first instance of Rand in God Mode), I could go on, but it's a bit of a broken record.

I think we should just accept that the momentum of the storyarcs in this series goes like this: agonizingly slow buildup laying a tower of cards made out of the thinnest glass on top of each other, and then a sledgehammer comes down on the whole thing delivering the conclusion and solution in one fell swoop.

So, come along, enjoy this fairy tale with me, and stop expecting it to be anything other than a well-woven yarn that has clear heroes and villains.