Are you talking about the garbled language that Harry couldn't understand (and neither could the reader) until Harry finally realized what Thomas was attempting to say? lol. I don't see that as bone headed, he literally couldn't make out what Thomas was saying.
I totally agree, also unless Thomas told him the whole plot, how would it have helped? What did Thomas tell him, a] Justine was pregnant, b] that he thought he was sterile because White Court Vamps usually are, c] he was nervous.
a] Take a and c together, seems normal, it isn't unusual for expectant fathers to be nervous. So where is the clue there? In addition Harry has had his own doubts as a father so he'd seen nothing out of the ordinary there.
b] Harry knows Thomas and Lara, both children of Lord Raith, he also knows several White Court Vamps who weren't found under a cabbage leaf somewhere, so perhaps WCVs are usually sterile but obviously not always.. Plus Thomas is only half vamp so what is there to be suspicious of?
I mean I remember guessing exactly that when I read it, as well as seeing several threads at the time that correctly predicted what was going on, so it can't have been that indecipherable.
Yes, for us readers sitting quietly, comfortable with a good drink, not that hard, but not that easy
either, not that many in those threads figured it out. Putting the reader in Harry's shoes, they didn't have to save his bother then help save Chicago, lose his lover, and finally bind and cage a Titan, so lets cut the guy a little slack, though he felt something was off about Justine from the start, he didn't have much spare time to work it out. If clever Lara couldn't figure it out, remember she is the one after it was all over, who insisted that Harry take Justine to visit Thomas to assure her that he was alive, how can we expect Harry to? However he finally did when he finally did have a moment to his exhausted self on the boat, just in time.
I think another interesting question along these lines would be why Nemesis would have given Thomas the mission then at all. It drives a hard wedge between the White Court and the svartalves, causing tension in the peace talks, but that's almost immediately put aside when Ethniu puts her foot down... literally. What was the goal with revealing Justine's possession to Thomas then? To tie up Harry's time? To what end? For new divides in the Accords?
Driving a wedge was what it was all about, but even Nemesis can miscalculate. Perhaps they thought that the Fomor and Ethniu would win, they hadn't planned on the star born Harry and a fallen angel/wizard/ hoodlum stopping, binding, and putting her in prison. Nemesis didn't want to reveal itself to Harry, it wanted inside the defenses on Demonreach, it was Harry who figured it out and forced the reveal in time to prevent it.