Hi I'm wanting some advice. While walking my dog she came loose from her lead another dog was near by the 2 barked and a short scuffle ensued before I got her back on the lead. It wasn't an attack or fight.  The other dog had a pre existing dog bite.The owner took her dog to vet and then delivered the bill to me said my dog had bitten hers in exactly same place. I phoned vet spoke to nurse who verbally contradicted this saying the pre existing wound had simply opened a little and needed 1 suture. No sign of a new bite. I have told the owner I'm not prepared to be responsable for the entire vet bill but she is insisting it my responsibility.  Having contacted the vet asking for written confirmation there was no new bite they obviously can't because of confidentiality, im having difficulty getting any factual evidence.how do I get the actual facts that will either prove or disprove a fresh bite has or hasn't occurred. 
If proofed  my dog did bite I'll pay. But will not pay all if it's not a bite. Any advice  welcome

If you can't sort this out between you, then you need the 'dog lawyer' - https://www.doglaw.co.uk/    Expensive but you should be able to minimise your costs if you get their advice over the phone.   I think you need it to shut this person down!   Actually I'm surprised you got that answer from her vet's office, even if it was from a nurse.   Generally speaking vets will usually only talk, at best, to another client's vet.

I would.take advise first. They arnt very expensive if u use their premium rate advise line up to £30 I think but it's all explained for u to decide when u ring 
If u pay up now effectively admitting responsibility and the owner changes their mind u could end up in some legal wrangle under the dda so be sure of the facts first