Interference then Collision-Did they get it right

[Rolliedogg]

Runner on 1st. Batter hits the ball into the gap. High School game.Runner of 1st attempts to score from 1st on the hit. As the runner approaches home, the catcher is set-up about 3-4ft up the line towards third. The pitcher is in the area and actually starts inching is way into the basepath about 6ft up the line(2 or 3ft from the catcher). The runner and pitcher make contact, enough that the runner is slowed. In another step or two, the runner and catcher collide. Bang Bang play hard to tell if the catcher touches runner, but catcher holds onto the ball as both runner and catcher tumble to the ground. Defensive manager complains, umpires conference, offesnive manager complains. The final ruling was that run scores due to interference by the pitcher, no out recorded. Runner is ejected for not avoiding contact with catcher. Player must now also miss the next game due to ejection.

Once interference occurs is this a dead ball and would that cancel anything that happens afterwards that is part of the play. The intention of the runner was that he would have slid wide and reached for the plate with his hand. But once the pitcher interfered, he had no where else to go. Opinions??