To be fair, it's pretty clear who made this a Helmet Debate issue:
Headway website says:
At Headway, we believe that all cyclists should wear helmets, particularly vulnerable road users such as children who do not possess the same level of competency or experience as adults. We believe helmets should be compulsory for all child cyclists while supporting calls for a range of additional measures to improve cyclists' safety, including more dedicated cycle lanes and educational campaigns aimed at both cyclists and motorists.
Cycle helmets should always be fitted and worn correctly, be free of any damage, and marked with the safety standard EN 1078 (for adults) or EN 1080 (for children)
Nope, in the context of this thread you guys did. You could have just ignored it. Thought, "nah, this one's not for me", but you didn't.
Rather than accept that the guy involved wants to pay back the charity that helped him turn his life around and learn to live with the injuries he sustained while cycling, by undertaking a pretty impressive challenge, you'd rather focus on the fact that the organisation holds a different point of view to you on one very narrow subject and use that to denigrate what he's doing and put others off supporting him.
As an atheist I don't particularly agree with Christian Aid's religious basis for its work, but I wont deny they do a huge amount of good and save lives. Nor would I actively go out of my way to discourage others from supporting them if they want to simply because I disagree with their view on a particular subject.