I don't know Brian Magee personally but he is hardly the type to deliberately cheat. Certainly seems like a decent guy and conucts himself like a gentleman outside the ring.
I put my detective hat on, went and looked up the case on the UK Anti Doping website. Found that the banned substance was Dorian Yates NOX pump. I then went and found the ingredients of NOX pump and checked whether beta-methylphenethylamine or Oxilofrine, or any of the other names those substances go by were listed......they were not. Turns out I partially wasted my time as if I had read on in the UK anti-doping case, I'd have seen the next paragraph read 'On 23 May 2013 UK Anti-Doping was provided with a copy of a report confirming the presence of both oxilofrine and beta-methylphenethylamine in the Supplement. The list of ingredients for the Supplement does not include either of the Prohibited Substances nor any known or recognised synonym.' So to answer your question, no.
Good interview on the BBC. Think the right result was got. He was very open with them and they found one of the things he was taking was contaminated. There needs to be regulation of 'Health' products in the UK,