s 25 Onus of proof as regards techniques and evidence.
(1) In any proceedings for an offence under section 23(1)(a) above consisting in a failure to comply with the general condition implied in every authorisation by section 7(4) above, it shall be for the accused to prove that there was no better available technique not entailing excessive cost than was in fact used to satisfy the condition. (2) Where— (a) an entry is required under section 7 above to be made in any record as to the observance of any condition of an authorisation; and (b) the entry has not been made; that fact shall be admissible as evidence that that condition has not been observed. (3) Subsection (2) above shall not have effect in relation to any entry required to be made in any record by virtue of a condition of a relevant licence, within the meaning of section 111 of the Environment Act 1995 (which makes corresponding provision in relation to such licences).