Potgieter's swinging arm was trying to dislodge the ball as Patrick Osborne drove low towards the line. There was no guarantee Potgieter's action prevented the try anyway. Sin binning him was unfair.
But it didn't have any effect on the result. The Waratahs were sliding towards disaster already.
Roll on the all-Kiwi final between two outsiders going into the season.
The travel factor is in the Hurricanes' favour. They'll have some home town advantage, although a good contingent of southern fans pop up all over the place.
But most importantly, the Highlanders will have to construct more than they did in Sydney. The Hurricanes won't take their tactics lying down, as the Waratahs did.
Joubert was touted as the world's best referee but shaky performances and decisions in this game, the 2011 World Cup final and last year's Super Rugby final dent his reputation. He might not be the best choice for the final this time.