I too don't think that Rocco was in any bad graces. There's no date and time stamp on the Trilogy, but based on the number of events that transpired between Michael's attempted assassination and Roth's murder, there must have been quite a bit of time that transpired. Thus, why does Michael leave Rocco alive during that time and seemingly fully participating in family activities? Doesn't add up.

Also, I can't see the assassins necks either or the I heart New York t-shirts they wore (since they look like they were hired out of New York).