This is a crazy theory and I never ever accused Kirkland before, but I don't understand something about him.
If he is willing to torture and kill people just for information about Red John, why did he not ask the guy in hospital about him? That guy was awake and alert, he wasn't in a coma, or anything..He could have threatened him easily. 
I've never been a fan of this Kirkland twin option, but now I think that twin in the hospital could have been Michael.

Kirkland is the only suspect for me who wouldn't even bat an eyelid while killing a child. He is creepy and emotionless. With the others, I can't imagine it that easily..

What if Michael wanted to kill the tygers and planted the bomb because they killed Bob? 

Anyway, I know it's messy, I'm just thinking out loud.:)