funny enough I had this towards the end of the season in a junior representative match. A player did a judo throw where his leg was very much involved. as he did it the ball carrier offloaded and I played on, but at the next break in play I told the tackler I didn't want to see it again as I considered it dangerous. 2 mins later he does the same thing, this time I blew straight away and gave a PK and gave him the bollocking it deserved! just after that he was subbed, however in the bar after the players father came up to me and asked me what the PK was for, so I told him that I believed it to be dangerous as it was in my view a trip and that he was lucky not to get a YC as I'd already warned him, the father said "you're a fool, he's been doing that all season" and walked off!
why didn't you give him a YC ? seeing as he had already had a specific warning?