^Oh, there were some that were frustrating as all getout. The absolute worst is when you have to kill whatshisface before he tries to kill Washington right after the gallows bit, and to get full sync you have to prevent him from killing either of the bodyguards and WITH melee. And pretty much the only way you can pull it off is by the completely random chance that he'll stumble into someone and trip and fall. If he doesn't, there's zero chance you can reach him before he reaches the bodyguards.
But if you get stuck on something, just watch how it's successfully done on YouTube. That always works.