Hi Rennie
There are a number of variables in your question however, hopefully this'll help ....
Did the Police attend and, if they did, did they aportion blame or charge anyone ?
How does the other driver know you were speeding .... I wasn't aware that the naked eye was an effective and accurate speed calculation device ?! Speed is difficult to accurately work out without the benefit of radar, speed detection cameras, calibrated speedometers on Police vehicles etc. Even the old fashioned method of measuring skid marks on the road is difficult with modern technology in most cars which prevent skidding .... ABS, Brake Assistance System, etc .... bottom line, someone saying you were speeding with no other evidence ain't gonna cut it ....
I assume the only matter in dispute here was your speed given you haven't mentioned anything else and, on that basis, the witness you make mention of who can testify that you weren't speeding, can they also testify as to what happened .... who did what, who was to blame, where the cars were positioned both pre and post crash ....?
Are they independent ?
What are your insurance company saying about the whole incident .... are they aportioning blame, disputing liability, etc ?
Dunno if I've helped or raised more questions ??!!
Cheers
S