Geaves as a published academic has a duty to stand up and answer all reasonable criticsm - it goes with the territory. However Geaves is also a paid lecturer at a UK public Institution - far more important than his accademic standing is his responsibility to provide balanced and competant teaching.
The Quality Assurance Agency for Higher Education:
http://www.qaa.ac.uk/aboutqaa/aboutQAA.htm
lists the following as key standards
Integrity
Professionalism
Accountability
Openness
I believe the Geaves has failed on every point and that reflects upon not just him but the Institution that employs him.