Just when you thought that the pervading narrative surrounding high tackles and head contact could not progress any further, there was another twist at The Stoop shortly before half-time of Harlequins’ narrow victory over Leicester Tigers on Saturday.

The hosts had just converted a penalty through Marcus Smith to take a 15-12 lead. They gathered Leicester’s restart and Joe Marler offered himself for a narrow carry close to the ensuing breakdown. It was the sort of lull that encourages spectators to switch into autopilot briefly – an opportunity to sip a drink or check your phone.

However, Calum Green lined up opposite Marler in Tigers’ defensive line and thwacked his opponent on the chin with his left shoulder. The Leicester lock was always upright and, from what we have come to expect from officials as rugby union attempts to crack down on high challenges, a red card seemed to be only option. But there would be another dimension taken into account.

Alex Dombrandt, initially in support of the carrier, had pushed his colleague into contact. This technique has become a reasonably common feature of battles for momentum on the gain-line. South Africa often deploy big men such as Franco Mostert and Eben Etzebeth in pairs, with one sling-shotting the other up-field. Dombrandt’s push was not drastic, but certainly looked as though it caused Marler to accelerate and to dip slightly.