It doesn't have to be used in a crime. All cell phone switch cell towers while you travel... your cell provider it keeps a timestamp log of this switching whether you use your phone or not. If you are suspected of a crime, all they need to do is guess your (plausible) location and see if your phone agrees.
Yes, I think you're missing the point of my original reply. The AC is saying that it's makes sense to him that the police can get records on cell phone on the idea "somebody builds something for you, and you use it in a crime, the court can order them to disclose what they know". I'm saying there is nothing here to suggest the cell phone was a tool used in the actual crime, so there isn't justification for the police to be able to get the records of the device using the reasoning he claims. It's just a case of "oh, gee, this idiot was carrying a device that happens to make it easy for us to get an idea where he's been, can we haz records nao?"