First: Will somebody kill 2 people just because he was humiliated. Will he be ready to risk his life, future, everything to settle a score. Not a strong motive in my view.
Second: Will Hemraj allow Raj Kumar to force himself on Aarushi when he knew Dr Talwar and his wife are sleeping on adjucent room. I mean will he not consider the consequences after that. Won't he consider what if Aarushi screams or what they will do after the act has been done.... Will they simply leave or will they kill Aarushi so that no one comes to know about it???? Before deciding to be a party to all this won't Hemraj would have known that this may lead to killing of Aarushi??? So was he ready to take the risk. Sounds unlikely.
Third: This story of CBI is too simple... Why did it take so long for a reputed institution like CBI to finally crack it.
Fourth: Why CBI also inititally pointed its suspecion towards Dr Talwar then and his custody was increased? Why did CBI keep on saying that Dr. Talwar is not co-operating and is hiding things. If this was the case there is nothing for Dr. Talwar to hide.
Guys, Small people like Krishna and others are being made scapegoad in this whole mess. CBI has to save his face or worse is acting on high command's instructions which is to protect someone influential.