I have known Dwain for more than 10 years and I feel sorry that he has been caught up in all this, but it would have been the wrong decision for sport, not just athletics, if he had won his case and gone to Beijing.
Since the British Olympic Association rule was brought in in 1992, every athlete in Britain has known that if you take drugs and you are caught, you are banned for life from the Olympic Games. From the moment you take those drugs, you take a gamble.
I grew up with people making mistakes, and I've made mistakes myself. But I am accountable for those mistakes.
The news about Dwain came through when I was on a train to watch the Golden League athletics in Paris with a group of about 30 young sprinters who have won the Street Athletics competition that Linford Christie and I have set up in deprived areas. Quite a few of the lads were making comments about the case, and they felt it was the right decision.
One of our winners from the last couple of years who has won the English Schools title said to me: "This has got to be the right decision. Otherwise it would send out the message that you can gamble with drugs, get caught and you can still come back." So they understand what is at stake here.
I first competed against Dwain at the 1998 European Championships, where I won gold and he won silver, and we both won gold in the relay. I think the only thing Dwain lacked then was mental toughness, but what he has been through this last year has shown he has become a tougher guy. That's why watching him is very sad for me, because that toughness is what he needed as an athlete. He never needed to take drugs at all.
Darren Campbell was talking to Mike Rowbottom. Campbell retired in 2006 after a sprinting career that earned him European 100m gold, Olympic silver at 200m and an Olympic gold in the sprint relay in 2004