These are things that IMHO decided this game:
1. The travels by Sully and Evan Turner - two silly unforced turnovers that came at key times in the game
2. The two bad fouls on jump shots from Bradley and Thornton - again both of these gave up valuable points
3. Horrendous officiating on the Lebron drive + hook against Jeff Green. No only did they NOT call the offensive foul (which would have given Boston the ball with a chance to increase their lead), but they eventually called a foul against Boston, putting Lebron at the line - a potential 2 or 3 point turnaround there from a single horrible call.
In a game that was eventually decided by a single possession, any one of those single events could have been the difference between a win and a loss.
I would add that when LeBron switched to defending Rondo it seemed to break down the entire offense.
Olynyk also missed a wide open 3 and Rondo a wide open jumper, sandwiched around a Bradley wild drive and lost ball. After that the only scoring with free throws by Green and Sullinger. On the other possession Rondo was stripped on a drive and the ball went off his foot.
Anyway, not assigning blame to anyone, just listing the horrible possessions down the stretch. They couldn't score at the end because they don't have guards that can get to the basket and finish or attract enough attention to open up other shooters. They also don't have anyone who, when the shot isn't falling or the offense is bogged down, can find a way to get to the line.
LeBron is just way too fast, big, and skilled for Rondo to hope to drive on, and the less Bradley drives the better. That leaves what? Pick and rolls/pops? Well as I mentioned earlier Rondo and Olynyk missed their open shots when they successfully executed the play. Sometimes they go in, this time they didn't.