Fob off

I jumped out of the Jag close to home the other day to dive into the supermarket, and let my partner take over for the short run home. Minutes later, I realised I had the key in my pocket. Did that mean she was sitting stranded with a ‘No Key Detected’ warning flashing, along with the ‘Your Boyfriend is an Idiot’ icon? Actually no (but yes); it allowed her to cruise home without the key and switch off, which seems strange. Is something wrong with the warning?