Ooh, that'd be interesting in and of itself, seeing Horatio from anyone else's POV.

That's one of the reasons I'm looking forward to reading this particular book. After being in Horatio's headspace all the time, it'll be interesting to try and guess at what he's thinking.

I have a nagging fear that it'll mean that Horatio's actions will remain ambiguous.

Yes, I get that feeling too. I imagine that Bush will be suspicious and Horatio evasive...