Ausfrosty
complete the exit condition report yourself and then make an application to fair trading for your bond.
its then up,to the landlord to prove the final condition. You may have to go to court if the landlord disputes your request.
you then need your completed final condition report. You may need your ex neighbour to testify that the landlord entered the property after you left.
if you have photos of the final condition all the better.
the above actions put the onus on the landlord to prove their claim.
i can’t see that you have done anything unreasonable.
Robert