De Novellis et al. (2020, hereafter DN20) studied the effect of mass extraction from a quarry on the occurrence of the Mw 4.9 Le Teil, France, earthquake of November 11 2019. This topic was also the focus of the report of the French working group mandated by CNRS INSU (“Groupe de Travail Teil” of Institut National des Sciences de l’Univers du Centre National de la Recherche Scientifique; Delouis et al, 2019). Despite using similar data and methods, these two independent research efforts reached contrasting conclusions. While both concluded the earthquake was possibly a triggered event (i.e. its initiation was possibly promoted by the quarry activity but its further rupture growth was primarily enabled by natural pre-existing stresses), DN20 deemed realistic the hypothesis that the earthquake was an induced event (i.e. both the earthquake initiation and its further growth, up to its final size, were caused by the quarry activity). This distinction is critical for our understanding of future anthropogenic hazards in the region and in similar settings elsewhere, and may have significant social, economical and legal repercussions. Here, we show that a severe error in the calculations carried by DN20 undermines their conclusion.