Banned Australia winger Reece Hodge said he had no knowledge of World Rugby's new guidance on high tackles.
He was given a three-match ban for a dangerous challenge on Peceli Yato in Australia's win over Fiji.
World Rugby said: "The player conceded he had no effective knowledge of World Rugby's 'Decision making framework for high tackles'.
"[He said] had not been trained on it... because [his] tackles are mainly in the waist to knees area."
Hodge will miss the remaining pool games with Wales, Uruguay and Georgia.
Yato had scored the game's opening try but after Hodge's tackle in the 25th minute he failed a Head Injury Assessment and had to be replaced.
The ban was reduced from six games because of "Hodge's exemplary disciplinary record, good character and conduct at the hearing".
The Australian escaped on-field punishment before going on to score his side's second try in their comeback win, and Fiji head coach John McKee said losing the impressive Yato so early "was a big loss ".