Scotland's players were unaware a knee would be taken amid confusion before their match against England, says head coach Gregor Townsend.
All but four of the Scotland team stayed standing, as did some England players and the match officials.
There was no directive from World Rugby or the Six Nations other than there would be a minute's silence to demonstrate opposition to racism.
"It was a surprise to our players," he told BBC Scotland's Rugby Podcast.
"I think our players closer to the English players saw that and made the decision whether to take the knee as well.
"We were strung out 50 metres for social distancing at the anthem. Huw Jones was at the tryline and Stuart Hogg was on the halfway line.
"So I know half the squad didn't even realise that some of their team-mates and the English players were taking the knee."
The gesture has not been part of pre-match protocols in rugby this season, as it has in football in the UK, and no players took a knee in the other two Six Nations matches over the weekend.
The day after Scotland's 11-6 victory at Twickenham, Scottish Rugby said it was a personal choice for players to take a knee or not, and Townsend reiterated that stance.
Asked if he thought more of his squad would have done so if they had been asked or had it been discussed, Townsend responded: "I imagine a lot more would have than did. But I can't say.
"If they didn't, and they wanted to choose to reflect that moment by standing up like they did in previous games, then that would be fine.
"They didn't really know that that was going to be the case. That was probably one reason why you only saw the players closer to the halfway line taking the knee."