By what can only be a happy coincidence, the requirement for "authority" in s 94(c) resonates with a remark by Roberts CJ in Georgia v Randolph, 547 US 103 (2006) (dissenting, joined by Scalia J): "A warrantless search is reasonable if police obtain the voluntary consent of a person authorized to give it." But the court's jurisprudence illustrates how this simple idea has been clogged with legal rules. For example Chief Justice Roberts, in the passage immediately preceding the sentence just quoted, summarised the precedents as including the proposition of law that " ... someone who shares a place with another cannot interpose an objection when that person decides to grant access to the police ...". I would argue that this should not be a proposition of law, but rather it should be a question of fact in each case whether a relevant occupier (the defendant) has given authority to another occupier to give consent to the search that actually occurred.
In Fernandez there was no such consent and the absence of the defendant, who was in police custody, did not result in him constructively giving his authority to consent to the co-tenant, and obviously, as there was then no urgency, the police should have obtained a warrant; the search was illegal and the admissibility of the seized evidence should be determined taking that illegality into account.