To make a claim for unfair dismissal on general grounds, you need to have been employed for 6 months; but claims based on sex and race discrimination can be made from Day 1. Though it isn't clear from you say, I assume your friend had not worked at the company for 6 months, so he wouldn't have a claim on general grounds. To claim on grounds of sex or race discrimination, he would have to show that a woman, or someone of a different racial group, had been treated more favourably than him. There would also need to be some evidence that this favourable treatment was due to this sex/race difference, rather than some other cause. If he really wants to take the matter further, he should seek advice from a Citzens Advice Bureau.