The dropping is done element-by-element, so some of the French judge's marks may have been dropped, some of them be equal to a marrk that got dropped, and some retained. Also, if you re-do everything without using the French judge's marks, you should also throw out the US judges marks.
I saw a chart that seemed to indicate that the French would have won even if the French judge's marks were excluded. But I don't think it took into account the fact that high and low marks are already excluded, but on an element by element basis. It just took the total mark for each judge.
With high and low marks excluded, one judge can't exert a huge amount of influence over the marks. You need two judges, one to be excluded and another to be not quite as biased, so be included. Also, a single judge can exert more influence by scoring the perceived opponent very low (marks to be dropped, of course). But no judge here put either of the top two teams in a very low place.
I would not place any credence in anything NBC says.
I think there are some systematic problems in ice dance judging: national bias, plus the tendency for a team to become "judges pets" and be treated generously no matter what they do (reputation judging). Neither one is new or confined to the French team. Chock and Bates themselves benefitted from it for several years.