Research on concerns about Emergency Remote Teaching has focused on teaching and management strategies, with some studies considering learners' satisfaction, reactions, learning and overall acceptance. The present case study, based on a survey on 3,183 undergraduate and postgraduate learners, aimed at investigating engineering students' self-reported experiences of the Emergency Remote Teaching. It identified the empirical factors characterising such experience and the predictors of the students' responses. Moreover, it focused on their reaction to the innovation in teaching and learning methodologies in an extreme scenario. Quantitative methods, like confirmatory factor analysis and factorial ANOVA, were adopted to analyse data. Our findings highlighted that engineering students assessed their overall online learning experience of Emergency Remote Teaching slightly negatively. This evaluation concerned their opinion about three factors which achieved different assessment. These results did not appear to depend on the learners' gender or their educational level of degree study, while the academic year of attendance seemed to influence their opinion on teaching. Moreover, the change in the learning approach experienced in the passage from bachelor to master's programmes was discovered to be a further predictor which might be more critical for females than males. Finally, implications for policy makers and higher education institutions for online learning in the post-pandemic scenario are discussed.