"If you have something that you don't want anyone to know, maybe you shouldn't be doing it in the first place." ~Eric Schmidt lol
except that the harmless written word is notoriously easy to quote out of context and otherwise use "against you" in court. At google's scale, it's virtually impossible to NOT have mountains of "incriminating" conversations. Also, it seems arbitrary that OTR chat should be recorded but hallway conversations and phonecalls are ok to delete...
Do you believe lawyers and judges are unfamiliar with this issue?
Like their entire lives are spent reviewing documents, letters and email. They invented the concept of Disclosure before computers existed, so that Defence can rebut or put proper context to any argument that will be made by prosecution.