Frankly I think it's well intentioned but a bit misguided. We talk of industrial accident, which after all regularly lead to prosecution. Whilst "accident" can sometimes refer to a random happenstance it does not specifically mean that. The phrase "accident waiting to happen" is commonly used and clearly implies culpability. To want to redefine "accident" to mean "no-blame" and then object to the use of the term is the wrong battle to fight and makes cyclists and safety people generally sound silly and more likely to be ignored .
It's not about that so much as accident is generally understood to mean at least
unforeseen or
not expected (if not
blameless) and depressingly many collisions are readily foreseeable and expected. Some are even predicted by cycling campaigners, such as I can tell you there will be collisions at certain points on local road layouts and skids and falls at others where the design is defective or the implementation flouts basic standards. Yet those collisions will be reported as accidents, even though they were foreseen and expected, so not really accidents.
It is not cyclists and safety people defining accident. They are merely reacting to what may be a changing use of language.
To use the word "collision" when someone falls of their bike or skids off the road even is bizarre [...]
That will be why the guidelines use "crash" for that, then. The petition doesn't mention it but I don't recall any legislation outlawing falling off one's bike anyway.
Not reading what you're objecting to makes people generally sound silly and more likely to be ignored.
Petition signed. It's a small move but there is little reason not to do it.