Indeed, instead of being a legal loophole, computer size definitions have always been the anomaly when compared to SI prefixes in use for centuries. When this started to become a significant problem (around the time when hard drive sizes moved into the GB range), a new standard was established based on binary for use with computer storage sizes. This is KiB, MiB, GiB, TiB etc. system (Kibibyte, Mebibyte, Gibibyte, Tebibyte), and has been around for over two decades IIRC, enough time that people should be used to it by now
But old habits die hard, and most people (including myself) still use the old system in casual settings. But whenever there is scope for confusion, it's a good idea to be clear about the intended meaning.