Good Question Kaz!
I have had this discussion several times with many "old-school" players and even officials as well as many "newbies" in the game and there is still a great discrepancy as to whether it is a 1 point or 2 point violation. Perhaps it is simply in the interpretation of the following WPA rules;
4.3 Opening Break Shot
The following rules apply to the opening break shot:
(a) The cue ball begins in hand behind the head string.
(b) If no called ball is pocketed, the cue ball and two object balls must each be driven to a rail or the shot is a breaking foul. (See 8.4 Driven to a Rail.) This is penalized by subtracting two points from the breaker’s score. (See 4.10 Breaking Foul.) The non-breaking player may accept the balls in position or may require the breaker to play another opening break shot, until he satisfies the requirements for an opening break or the non-shooting player accepts the table in position. (See 4.11 Serious Fouls)
8.4 Driven to a Rail (From definitions used in rules)
A ball is said to be driven to a rail if it is not touching that rail and then touches that rail. A ball touching at the start of a shot (said to be “frozen” to the rail) is not considered driven to that rail unless it leaves the rail and returns. A ball that is pocketed or driven off the table is also considered to have been driven to a rail. A ball is assumed not to be frozen to any rail unless it is declared frozen by the referee, the shooter, or the opponent. See also Regulation 27, Calling Frozen Balls.
4.10 Breaking Foul
A breaking foul is penalized by the loss of two points as mentioned under 4.3 Opening Break Shot, as well as a possible re-break. If both a standard foul and a breaking foul happen on one shot, it is considered a breaking foul.