Being 'clutch' is not just hitting a shot in the last few seconds. It's also making the great pass, getting the key rebound and also putting the team in a position to win during the fourth quarter.
Saying that Ray is 'clutch' is true but I would say Bosh was even more so. Sure, they wouldnt have won without Ray's big shot but without Bosh's blocks the same can be said.
And, Lebron's whole fourth quarter was pretty much clutch.