What makes Franco offside?

The Hurricanes have possession but Rodney So'oialo, with the ball in his possession is tackled and brought to ground. Todd Clever of the Lions tackles So'oialo who falls at the feet of Ross Geldenhuys. Geldenhuys immediately tries to get the ball from So'oialo but Andrew Hore and Bryn Evans drive into him. Geldenhuys, Hore and Evans go to ground. The next player to arrive is John Schwalger who crouches over the ball and players on the ground.

Franco van der Merwe is on the side of this and moves forward. The referee calls: "Advantage. Offside."

At what stage was Van der Merwe offside?

There is only one ruck in this sequence - when Hore and Evans drive onto Geldenhuys.

Where was Van der Merwe then? On the side beyond the last feet.

What Schwalger did, crouch over ball and bodies without physical contact with a Lion did not constitute a ruck

Presumably the referee penalised Van der Merwe for being ahead of that short-lived ruck when Hore and Evans met Geldenhuys.