I don't think so--how can anyone predict the actions of Joffrey? He was such a--well, I don't like using those words.
This was a crime of opportunity, not planning.
What about the fool who came to Sansa during the incident and tried to drag her away from the scene? I don't think Tyrion had anything to do with it--it was Sansa and the fool.
No, Tyrion had nothing to do with it. But I don’t think Sansa did either. I think the fool and grandma Olenna set up Sansa with a “special” necklace. The act of the fool randomly giving her a necklace coupled with the scene where grandma had all those necklaces on a table but liked none of them well enough and instructed all those maids to go out and find more. Plus at the wedding feast when Grandma was playing with Sansa’s hair and fingered the necklace she was wearing that the fool had given her, it looks like afterwards you can see one of the stones is missing.