All good points.

I've often wondered about Tom's relationship with Rocco and Neri. He was solid with Tess and Clem because he was raised by Vito as a son (they might have been like his uncles). Vito trusted Tom completely and had appointed him consigliere and made him his official go-between when handing down orders. But, Michael never really warmed to Tom--he was Sonny's choice for a brother, not Michael's; Vito's choice for consigliere, not Michael's. Michael fired him as consigliere in GF. And, just hours before the Tahoe shooting, Michael had introduced Tom to Johnny Ola as "my lawyer," and said Tom would not sit in on the Havana negotiations--a real humiliation. Rocco and Neri were the trusted parties for that deal. They probably had no respect for Tom because he was not Michael's consigliere, was not Italian, and hadn't come up from the muscle side of the business. And, as Luca pointed out, everything after the shooting happened so quickly that Rocco didn't even know where Michael was.

So, we have to wonder: how if at all did Michael communicate that Tom would be in complete charge while he was away--and that they were to obey his orders as if Tom were Michael? It must have been especially tricky for Tom because, as Michael told him before leaving, he couldn't completely dismiss the possibility that Rocco and/or Neri were in on the shooting.