Here's how Peter O'Mahony has been binding at the scrum, going under Archer's leg, rather than over Kleyn's back.

It means O'Mahony has essentially been a third second row tonight.

Only issue, it's not a legal bind. Should be a Leinster penalty. pic.twitter.com/MuzjXMKeFM

— Neil Treacy (@neil_treacy) October 6, 2018