Hi Jean,
Thanks for this but it won't work in a lot of instances. For example, I have a button that slows down the characters walk speed and rotation to allow them to fine tune their aim. Currently if I use Set Animator Play Back Speed to 1/2, it will result in her shooting in slow motion as well. If I try to employ the workaround, I'd have to create additional states in Mecanim for every single animation other than aiming and firing. I realize it's an API thing, but please check if Unity resolves it in future releases.