Last week my wife was stopped just after a junction by a Police Officer.
There was no accident a little matter with various cars trying to cross.
She explained what happened.
The Police Officer started to berate her and contradict her story.
She listened patiently.
Then she said "Office, I hear what you said, but would you like to look at it on the Dash Cam recording?"
The Police Officer backed down and said " I am not here to waste time, please continue on your way".
Moral:
Get a reasonable quality (looping) 'Dash Cam' as they are not very expensive and they can stand you in good stead in various circumstances.