I am really confused here....... How could the Silver hands possibley get into Jarrvaakr and kill Kodlak? I mean I thought the Companions was an ELITE Guild? But yet they let a couple of silver hands kill their LEADER? I just don't understand this!!!

Because YOU weren't there.
Why weren't you there for him??
He had such high hopes for you.....

Yeah, Sure. I was DOING what was asked of me!

Well I hope it was worth it!

Just about any bodyguard or protection unit will tell you that if the Assassin is willing to give his/her life to complete the mission it is incredibly hard to stop them. Simply put, wait until he steps outside and mob/jump him and not care what happens afterward means success most of the time.

yeah how they got past the city guard and got past Aela the Huntress even...

Those silverhand die a lot now. I return to their hang outs and kill anything unfortunate to have respawned.

And I should have been there instead of collecting heads... Silverhand should have known better. They killed Skjor so I killed about 20 of them... They killed Kodlak. I killed ALL OF THEM!

Seems they made a mistake.