I find this reasonable; you wouldn't sue the manufacturer of a recording device if someone made a secret recording with it. I do think this means that the smartphone owner is liable, and should be fined or jailed.
But in this particular case, it's the company doing the recordings, not the owner of the device, so it's a slightly different situation, in my opinion.
That said... The owner could be liable if for example it were necessary to explicitly inform of the existence of such devices the possibility of being recorded.
That said... The owner could be liable if for example it were necessary to explicitly inform of the existence of such devices the possibility of being recorded.