The All Blacks captain could be facing a potential citing after putting in a reckless low shot on flanker Lucas Rumball in the 23rd minute, which may have made contact to the back of the Canadian's head in Otira, Japan, on Wednesday.
After getting back up to his feet, Rumball made gestures of disgust to Read's tackle.
Referee Romain Poite initially missed the incident but would later give Canada the penalty advantage after his fellow official spotted the tackle.
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Despite not being further punished during the match, the tackle may be investigated by a judicial hearing which has seen several players receive post-match bans during the tournament so far, as World Rugby stamps down on head contact.
Thus far, head contact has been ruled to the letter of the law by World Rugby officials and judiciary, regardless of intent.
Under World Rugby's current high tackle framework, Read's shot may be considered a high tackle because of the possible contact with either the head or neck.
The tackle then could be deemed worthy of either a red or a yellow card depending on the "degree of danger".
If the tackle is deemed to be an act of foul play that warranted a red card, Read could be facing up to a six-game ban which would mean he would miss the remainder of the World Cup.
However, even if Read is deemed guilty, there are mitigating factors which could reduce the sanction. Teams also have the opportunity to appeal any decision.
Earlier in the tournament, Wallaby Reece Hodge was banned for three games for a tackle on Fiji's Peceli Yato. Like Read, Hodge's tackle wasn't deemed to be a red card on the day but the winger's tackle was referred to a judicial hearing.
The disciplinary committee "deemed that the incident was an act of foul play and warranted a red card in line with the high tackle sanction framework", World Rugby said in a statement.
It added that the tackle was "reckless, rather than deliberate", but contact with the head meant a high degree of danger.
In Hodge's case, Fiji was the one who referred the incident to the match's citing commissioner. (Teams have 12 hours post-match to refer any incident – which has passed in the case of the All Blacks.) However, the commissioner also has 36 hours to cite a player themselves for an act of foul play believed to warrant a red card.
If Read does get cited, it comes down to whether he is deemed to have had an "exemplary disciplinary record, good character and conduct at the hearing" by the disciplinary committee.
After the All Blacks' first game of the tournament against the Springboks, Read was criticised by some fans and pundits for what appeared to be a coat hanger type tackle around South African flanker Pieter-Steph du Toit's neck. The All Black skipper wasn't cited or punished for the incident.
Read was yellow carded once in the 2015 World Cup.
So far, five players – Hodge, Samoa's Motu Matu'u and Rey Lee-Lo, USA's John Quill, and Uruguay's Facundo Gattas – have received three-week suspensions for dangerous tackles.
