A YouTube spokesperson didn't directly explain the cause to CNBC, but said that the company sometimes "make[s] the wrong call" with its algorithms.

The incident underscores YouTube's ongoing issues with automation. While the site needs algorithms to moderate the massive volumes of content uploaded every day, it's not prepared to handle every possible situation and may have shortcomings that aren't immediately evident. Unfortunately, YouTube is discovering this flaw in the midst of a sad moment in French history.