Thursday is theory day now.
This is the fourteenth article of the series. Since there are a lot of theories floating out there and I'm asked often enough what I think of them, I thought I write it down. You can then laugh about me when I am totally proven wrong by "The Winds of Winter" or something like that. Rules are as follows: you put a question about any theory or plot element (really, let's stress "theory" a bit for the sake of interesting questions) either in the comments of any theory post or by mail (email@example.com) and I will answer them in an upcoming post. And if you now ask "Stefan, isn't this a shameless rip-off of Sean T. Collin's "Ask me anything"?", I would tell you to shut up, because you are right.
Prepare for part 14. Spoilers for "A Song of Ice and Fire", obviously.
Why did Olenna Tyrell go through all the trouble with the hairnet?
The most important point here is deniability. The hairnet was given to Sansa by Dontos, who in turn and unbeknownst to anyone was paid by Littlefinger. Should anything have gotten astray, Dontos would surely have been killed in the chaos, and the trace of the poison would have been cut off on the spot. While it is true that nobody was searched, you don't want to have a deadly poison in your pockets, at all. Imagine something going wrong and people are searched. Perhaps a chip of the poisonous stone broke off in Olenna's pocket and is found? Why take such a risk? This way, there are multiple fail-safes. Sansa carrying it allows to blame Tyrion or even Dontos, whatever is preferable in the given situation (nobody could anticipate just how the wedding would escalate between Joffrey and Tyrion). The scheme also allows them fail-safes should anyone of the conspirators get cold feet or change sides, since there is no proof. Imagine Littlefinger deciding to carry favor with Cersei, and Olenna has the poison in her pocket! You definitely wouldn't want to fall into that trap. This way, it's much safer. Besides, Olenna and Littlefinger both consider themselves master-players, so it seems likely that they would be willing to conceal themselves in such a fancy way instead going for the easiest solution.
Perhaps it wasn't Olenna after all, but Garlan who commited the murder?
It's not like we could rule this one out, of course, but there is no evidence for it. Garlan seems like a nice person, allright, and that in and of itself is conspicious. But why would the Queen of Thorns or Littlefinger resort to the man who sits exactly next to the guy they most likely want to blame? Tyrion is far away from Joffrey, and as far as we know, Garlan never gets near the high table to put the poison in Joffrey's chalice, whereas Olenna is perfectly suited for the task. My guess is that Garlan isn't informed at all. I wouldn't really consider him as a player of the game. He seems more the Kevan Lannister type, a decent guy following his superiors and loyal to the family. He does what he needs to do, and for the rest of the time, he just lives his live. He doesn't seem the type to partake in such a conspiracy and amiable chat with the guy they want to blame for the murder.
Many kingsguard are likely to be out - Kettleblack at least, perhaps even Loras and Jaime. Who will take their spots?
I think this question is almost impossible to answer. The qualities required in a kingsguard - keeping your mouth shut, being a decent sword and loyal to the king - are not exactly the qualities that we have in our POV characters. I would guess that if the names of the next kingsguard are known to us at all, they will be minor characters at best. The question is a highly political one, though. As of the end of "A Dance with Dragons", the kingsguard technically is complete. We have Boros Blount, Balon Swann, Robert Strong and Meryn Trant in capacity, Loras Tyrell wounded, Jaime Lannister missing and Osmund Kettleblack incarcerated. As long as none of them is officially dead or stripped of the white cloak, the guard is down to four men. When a spot opens - which is most likely in regards to Kettleblack's - the pressure will be such as to appoint someone worthy, i.e. someone reasonably highborn. However, neither Lannister nor Tyrell will allow for a kingsguard that is too closely affiliated with the other house, so expect a choice that won't infuriate anyone. Possibly, they would want to give the spot to some fickle ally, like a Dornishmen or knight from the Vale. Perhaps even a knight from the Riverlands could fit. The question becomes more interesting in Loras' and Jaime's case, since both are affiliated heavily to their houses. If Loras dies, the Tyrells will want to install another man loyal to their house. If Jaime is declared dead, the Lannisters will want to appoin the next Lord Commander themselves. None of the previously mentioned four remaining kingsguard qualifies for this, so they would need to appoint and promote someone at the some point. All of this will diminish the reputation of the kingsguard, so the persons appointed need to be paragons of virtue. No easy choice, and no wonder no one has made any move yet.