No kidding, any Maps user can see their GPS location being collected when they use Maps. I think mynameisvlad may mean they wouldn't necessarily know if you stopped at a specific place as part of the location data collected when you're not using Maps, because in that case it may not use GPS. But I have a nice phone, battery life isn't really a concern to me, some software on the phone probably knows that too, and I don't trust the word of a random person on HN that the software wouldn't do an opportunistic GPS look up at least every now and then. In any case I want my phone to use GPS whenever it can so that it's as accurate as it can be, that's why I have in my settings GPS always enabled, with high accuracy (uses GPS, wi-fi, and mobile networks) and indeed I have Google Location Reporting on as well which looks up my location throughout the day whether or not I'm using Maps.
Because in this instance, the argument/discussion is about the phone specifically, not Google Maps. When my phone is on stand-by, like when I'm driving and not using the GPS, the phone will rely on less battery-taxing things like triangulation, Wi-Fi AP's that Google knows (MAC/SSID ?). Google Maps would however use GPS when it is on, not when the user hasn't specifically turned it on.
It's you who's confused (as you said previously, no offence). The post you replied to talked about "I just drove half way across the UK. Google knows that because I was using Google maps", and the mention of not using highest resolution is about Google (not Maps) using other means to determine location. Clear difference between Google Maps and Google.
Silly technicalities, don't know what the downvote was for, was only trying to help your initial confusion :)