Turnbull hit it directly on the head. Great post.

I too think it was a little of both, he still did not know who was involved until he caught Fredo in the lie when they all went out. That would be the reason he had a bodyguard outside the family, he knew he had no way to be back stabbed once he stepped onto the island.

I will admit Turnbull I had no idea what the bodyguards name was. Shows how dumb I am on the movie.