Q: >>How would I or anyone know if you did present a paper, researched it or what.
A: Maybe because generally conference proceedings and papers are published and as such the existence of the paper would be much easier to verify than some of the opinion based comments you have put forward??: Comments involving sarcasm and personal attack provide nothing to an argument, and credibility does not necessarily burst forth from claims such as 'christopher reeve would have been killed without a helmet'. Instead of anecdotal evidence based on the experiences of celebrities - i'd rather trust in peer reviewed journals. I can't remember whether it was on sydney cyclist or elsewhere but i have previously seen a literature review on the helmet issues and whether with/without is better in a bad accident certainly isn't clear. It is very difficult to collect data on the effect of helmet wearing versus not in a crash, because there is never really objective crash data (in terms of the physics of the collision), there are too many variables for computer models to work and you can't run controlled experiments! (ethically - ha ha)
There are definitely multiple publications demonstrating that helmets can increase the likelihood of torsional injuries because the shape of the helmet can rotate the head on impact. These torsional injuries tend to result in greater loss of function (or higher chance of death) than a more direct head impact.
I've also seen comments from helmet manufacturing engineers based on in-house testing saying that in the case of a heavy impact there would be basically no difference between wearing a helmet or not as bicycle helmets are not designed to resist extreme impacts. Probably horse-riding helmets are tougher, and motorbike helmets are tougher again, bike helmets are most useful when you don't hit your head very hard.
Furthermore, there are actually very few studies demonstrating the benefits of helmets and none of them have had clear cut outcomes that aren't controversial. Apparently the study used to justify compulsory helmet wearing in australia is of particularly dubious scientific merit.
Having said this I always wear a helmet (in australia). I would always wear a helmet on my road bike anywhere, but i might not wear one for small trips to the shops, etc, given the choice, as i've done when riding hire bikes in europe as a tourist. This is not an attitude based on logic or research, but based on what feels safe to me. Logically i know in some types of crash there is evidence to suggest I'd be better off without a helmet, but having had some accidents I definitely feel better wearing one in a situation where I'm riding quickly, doing fast corners, steep descents or in fast traffic. But in low traffic zones in my local area when i'm just cruising around I'd say the only reason i wear one is to avoid being hassled by police or yobs in cars.
Links containing EVIDENCE for/against:
1. contains links to peer reviewed publications for/against helmets
2. paper with an anti-helmet bias, but makes some good arguments at a societal level that there is a net health benefit of allowing freedom of choice for helmet use. Interestingly car driving and being a pedestrian are more likely to kill you per miles travelled, and that motorcycle riding is insane!
The graph below shows that countries with greater cycling participation have far fewer deaths per kilometre ridden; and that helmet laws are associated with much lower cycling participation - and hence a relatively higher death-rate: