However, the key word here is 'liable' because during a game of rugby, players find themselves offside on numerous occasions.
It would be a miserable game if the referee penalised every offside player during the match.
Such offside players can immediately become onside if they retire behind their offside line, in this Border case being behind the hindmost feet of their team in the ruck.
Clearly, Fred Dagg could see this wasn't happening.
The other two ways they could have been put on-side was for an opponent to kick the ball, or if one carried the ball at least 5m in any direction.
And this is in fact what happened.
Ruapehu won the ball in the ruck and the halfback ran the other direction away from the offside players and kicked the ball into touch further up the field.
So, although the two players Fred Dagg was going on about were technically offside, the referee allowed play to continue as the ball went away from the offside players because they had no effect on play.
Had the ball and Ruapehu halfback come out on my side of the field, in the direction of the offside players, I would then have indicated to the referee they were offside and should be penalised, because they were benefiting from their illegal position.
Offside players may be penalised if they fail to retire behind their offside line without undue delay and could benefit from being put onside in a more advantageous position.
If the player is clearly retiring when he is put onside by an opponent running 5m with the ball, or kicking it, then he can re-enter the game fairly.
However, if he is making no attempt to get back onside because he is merely standing and waiting to be put onside, then he would definitely be liable to be penalised because he has benefited from it when he re-enters play.
A penalty kick would apply if he moved towards the ball or interfered with play in any way.
Offside play at a ruck, maul, lineout or scrum differs somewhat from the offside for what is now called open play, formally general play.
All sorts of interesting things can happen out in the open.
Generally speaking, a player is offside if he is in front of the team mate carrying the ball, or who last played the ball.
If the ball has been kicked by a team mate who is behind him, the player must stop and cannot advance until he has been put on-side.
This can happen if the kicker, or anyone who was behind him when he kicked the ball, runs past him.
Or, after stopping, he can retire behind any onside teammate such as the kicker or those coming from behind the kicker.
However, if the offside player is within a line, running across the field, which is within 10m from where the kicked ball is about to land, he must physically begin to retire behind that 10m line immediately.
Offside players in open play who are retiring (and are more than 10m from where the ball is landing) are put onside if an opponent attempts to catch or gather the ball but fails to do so.
At that point, they may go for the ball themselves.
They can also be put on-side when an opponent carries the ball 5m, kicks it, or passes it.
That means if an opponent carrying the ball passes the ball to the offside player, he is then onside and is free to turn around and do whatever he likes with the ball.
Opponents who may know the name of the ball carrier often call his name out in the hope he will pass the ball to them.
This situation often causes consternation among players of the ball-carrying team because they think the opponent is offside but not so – the pass from the ball-carrier automatically puts them back onside.
Now, that really could have sent Fred Dagg into another frenzy, had it happened in the semifinal.