I think the bug exists for quite a long time. For example, warrior shield 5 and dagger 3 can be interrupted and hence on a 3sec cool down. I think there are other skills have the same issue.
I acknowledge that this has something to do with animation and hence might be hard to fix. But a easier solution for those skills is to remove the 3 second cool down after being interrupted and more importantly, remove the increase CD if being interrupted by mirage.