Like another poster said I think that last scenario depends on who is doing the double team. Westbrook should probably set the bar on how fast a defender should be able to recover back on a pass back out.
Speaking of momentum, for defenders jumping/closing out at shooters, there were two problems with 2k12 IMO. A) there were certain instances where amount of momentum before a jump and during a jump did not match well, - like a player could go from standing still to doing a super jump at shooters from behind picks and b) players jumping at you full on 100% turbo didn't have any momentum recovery when they landed, so they were back in play once they landed
Example of what I expect with b) is at the 1:00 mark of this video (i believe that is monta ellis almost knocking down Stan Van Gundy). Players usually take a half second to a full second to recover from a jump like that to make sure they don't fall awkwardly.
http://www.youtube.com/watch?v=99lLAzJbs-Q