“in assessing whether extradition was compatible with the applicant’s Article 8 rights, as well as those of his partner and child in Poland, the District Judge heard the applicant in evidence. The absence of documentary evidence to prove his employment and payments to his child was identified in the factual findings made but was not a significant factor in the District Judge’s balancing exercise between public interest and Article 8. The fresh evidence, the absence of which in the extradition hearing is not explained, would not arguably have made a difference either to the decision upon the balancing exercise or the decision to grant extradition.”