This should be complete before the patient goes into the OR, well before the time out. An unwitnessed or undated consent is not considered complete.
If I need to witness a consent that I did not watch the patient sign, I show it to them and ask "is this your signature? Do you understand the procedure and have all your questions answered?" If they agree that they signed it, I'm ok with that. If they are sedated/ confused/ parent or guardian signer not present then I leave it in the hands of the person obtaining consent and do not witness it. Of course this all happens BEFORE the procedure. You should never assume consent unless it is life or limb. Even then we still try if reasonable.
