"(1) An employee who is dismissed shall be regarded ... as unfairly dismissed if the reason ... for the dismissal is that-
"(2) For the purposes of subsection (1)(e) whether steps which an employee took ... were appropriate is to be judged by reference to all the circumstances ..."
"In the light of our findings of fact above, the applicant has not proved that the reason for his dismissal was that, in defending himself he took appropriate steps to protect himself from serious and imminent danger."
"(4) A comparison of the case of a person of a particular racial group with that of a person not of that racial group under section 1(1) must be such that the relevant circumstances in the one case are the same, or not materially different, in the other."