The application of the disciplinary measuresto a secondary school teacher in the Community of Madrid is analyzed by means of the resolution of the case study exposed. Said teacher, while in a context of blended teaching, suspends his online teaching activity of his own will, infers serious accusations online against a student and her family in the presence of the other students, disregards the principal’s orders and directs accusations and threats to the management team by e-mail.It is about the guaranteeing of the adequate educational support in a COVID-19 context and the responsibilities of teachers, in coordination with the ICT coordinator, in the use of teaching platforms. It also examines the appropriate weighing of teachers' actions within the framework of the disciplinary procedure through the application of the principles of guilt and presumption of innocence.