Using a timer with a Voice assistant but not with the switch

I just setup Google Home for use with Home Assistant. My question is how can a trigger in an automation differentiate between using a voice assistant vs using the manual switch. I want to setup a light to have a timer to automatically turn it off after using Google Home to turn it on, but when using a switch, or even the Home Assistant app, it will stay on without the timer. I am trying to setup a way for my teenager to turn on the driveway lights with Android Auto when she comes home from work. She will most definitely forget to turn them off. I can easily setup a timer for this, but… If I want the lights on for longer, as I am less likely to forget to turn them off, I want a way to keep them on.