Stolen bikes

Don't want to crap on your most excellent story. Main thing is you got the bike back and the thieving shit got arrested. The cops almost always get given a hard time here regardless of the results and fact is they helped you get your friends bike back.

Police cells aren't known for their roof gardens or panoramic views, I'd be amazed if the scrote could get a signal even if he did have his phone on him for a bit while in the cell. Think about how many times you can't get a signal while inside a building, then think about how thick the walls are of a typical police cell.

Depending on how much they care, thats a very well defined time window to see who he called if they go after the cell records/look at the call log on the phone.