Bit late in on this one, Geezer, but it is interesting.
I did not see it live but only heard about it when, during an interval in the final, Steve Davis interviewed referee Jan Verhaas and the issue was explained.
The first thing I did not understand was why the frame had not already been awarded to Higgins after Ronnie had made three misses (under the “three miss” rule). This rule states that the frame will be forfeited when three successive misses are played “...when there was a clear path in a straight line from the cue-ball to a ball that was on or that could have been on, such that central, full-ball, contact was available”. As far as I could see the black was in such a position that it could have been struck centrally. However, the red nearest the cue ball may just have been preventing this and perhaps this was pointed out during the live commentary.
Putting that aside, I do not think a rule change is necessary. It is clear that Higgins was disadvantaged by Ronnie’s foul. However, unlike footballers, I do not think professional snooker players generally seek to gain an advantage by exploiting the rules to the limit. I don’t think for one minute that Ronnie committed the foul intentionally to get out of a scrape (indeed he seemed as bemused as everybody else by the ruling) so we are unlikely to see a recurrence of this incident.
Further, as Jan Verhaas pointed out, the referee has the discretion under Section 5 of the rules “to make a decision in the interests of fair play for any situation not covered adequately by Rule”. Jan himself said that with hindsight he perhaps could have made a ruling under that section and I imagine that is what any referee may do in the unlikely event of a recurrence.