The Heat's role players missed their shots and the Pacers missed their opportunity
Sure, the Pacers are an excellent team and the Heat certainly will have to earn it, but LeBron James is not going to have to drop 30-10-10 to win each game, as Charles Barkley suggested.
To say nothing of the other two members of the big three and the Heat's tendency to come out slow in game 1, the Heat's role players alone should be enough to lighten the King's load.
Chris "Birdman Birdman" Anderson had a great night, scoring 16 points on 7-7 shooting and two big free throws, but the other role players didn't contribute much. Even with Anderson's explosion, those six role players (Anderson, Allen, Battier, Cole, Chalmers, and Haslem) combined for 37 of the Heat's 103 points, the lowest percentage of the team's points in any game in these playoffs (the second lowest came in game 1 against Chicago, the Heat's only loss).
Chalmers shot relatively well before leaving the game with a shoulder injury, but the other four players shot a combined 3-22 and scored 11 points.
LeBron played a wonderful game and the analysts are correct in saying that he probably won't play that well in each game. But the role players will be more effective in the other games, so the Heat won't need such a heroic effort to win.
Typically Ray Allen doesn't go 1-8 and miss a free throw to ice the game. Shane Battier usually doesn't miss all of his field goal attempts, and Haslem, Cole, and Chalmers always seem to contribute offensively down the stretch.
Indiana's defense is good, but it doesn't explain why the role players missed their shots. The Heat shot 47% last night, but their shooters were just missing shots they usually make.
This was the Pacers chance to make something happen in the series but they couldn't take advantage of it. In the Bucks series, the six Heat role players I mentioned scored 49.75% of the Heat's points and in the Bulls series they scored 47.25% of the points. The role players are going to contribute more moving forward, and as long as they chip in around 40% or more of the team's points, LeBron's burden will lightened and the Heat will be just fine.