Hi, sorry, and maybe I described it wrong: What you are suggesting is not working in this case. OS X is telling us ( regardless with or without the ctrl-key pressed ) that the program is defect and ask if it should be deleted !
So the sudo is the only way how you could get it up and running. It is interesting as the DMG file mounts well, the installation also works. But when you start the app it will show the error.
Anyhow, I think you should get your signing fixed.