I Hear Enemy Recalls

Tristana and Blitzcrank (both enemy team) just finished off some of my team's creeps by our bottom tier 2 tower (tier 1 was destroyed). I somehow had vision (not a ward) of them in the "deathbush"* (I don't think this was a bug but i could be wrong) I saw that trsit had started her recall but blitz hadn't so as Ahri, along with kha'zix flanked them. I could also hear tristana's recall very clearly while I had vision. The short period of time that we had vision had worn off and it turned to fog of war but we were close. I could still hear tristana's recall even though i couldn't see her so I waited to make my assassination once she was gone then proceeded in killing blitz.

I shouldn't be able to hear the recall while she's in the fog of war should I?

*by death bush im referring to the small bush located between the tier 1 and tier 2 turret along the edge of the map

This happened just now post patch.

I haven't tried to replicate it since.

*by death bush im referring to the small bush located between the tier 1 and tier 2 turret along the edge of the map