Litigation privilege applies to non-confidential communications between a lawyer and third parties, it exists only in the context of litigation, and it ends when the litigation (and all closely-related litigation) has ended. It is based on the need of the adversarial process to provide a zone of privacy to facilitate investigation and preparation of cases for trial. Solicitor-client privilege protects a relationship, while litigation privilege protects a process.
Blank v. Canada (Minister of Justice), 2006 SCC 39 at para. 28.
Although all statements of Crown witnesses must be disclosed to the defence before trial, there is no reciprocal obligation on the defence.
R. v. Stinchcombe,  3 S.C.R. 326
There is no traditional litigation privilege over Crown witness statements made during interviews with Crown counsel in preparation for trial. This is because the Crown cannot claim privilege over that which it is obliged to disclose.
R. v. Malik, 2003 BCSC 1709 at para. 9.
Litigation privilege attaches to defence witness’ statements made during interviews with defence counsel in the same circumstances.
However, an accused implicitly waives litigation privilege over the witness’ statement when the witness has read the document either while testifying or at a reasonable time prior to testifying, and that this has assisted the witness to refresh his/her memory in some way.[FN]
R. v. Mitchell, 2018 BCCA 52, at para. 45.
When the accused chooses to refresh his memory from notes to which litigation privilege would otherwise apply prior to taking the stand, the Crown is entitled to see such notes subject to the court’s discretion.
R. v. Sachkiw, 2014 ONCJ 287, at para. 62.
The Crown is entitled to explore through cross-examination the impact of the statement on the witness’ recollection of the events in question and to use the refresh statement in cross-examination to test the reliability and credibility of the witness.
R. v. Mitchell, 2018 BCCA 52, at para. 38.
[FN] Different considerations may apply in respect of notes made by or for an accused who testifies in his own defence, as solicitor-client privilege may be operative.