Exactly, it also has to be proven beyond reasonable doubt. That's an extremely high burden of proof.
Yes poor wording on my part, the cyclist did contribute to the accident by being in the door zone but clearly that isn't the cause. They cyclist broke a bone in her knee, no damage to the bike or the car, no corroboration at all, one word against another.
Incidentally one word against another is 50/50, that's a not guilty verdict straight away.
In addition the highway code says you should "Leave plenty of room when passing parked vehicles and watch out for doors being opened or pedestrians stepping into your path" when cycling. No defence solicitor in the world would not bring this up in court. The driver was adamant they checked and nothing was there, they then opened the door only 6 inches before the cyclist hit.
Not easy to make a decision is it? Proceed and you are potentially wasting thousands of pounds of taxpayers money, don't proceed and the car driver potentially gets away with an illegal act.
I might add that I was swinging in favour of prosecution but once I'd discussed it with supervision the lack of any independent witnesses killed it.