Secret alert- triggers camera?

Yes.  Any alarm event, including a secret alert, causes the camera to record.  This is not something which you can control.

The secret alert won't show when the door closes.

Why do you care that the camera records?

@jonkaterba , to be truthful, I had same thought as sevensiamesecats, but you do make a valid point.

Please excuse the sarcasm in the following as its for Simplisafe....

@jonkaterba , good point and you can easily make your suggestion on this feature change by heading over to the "Suggestions Box" at the Customer Resource Center and submit it to SS there.  Easy for customers, easy for Simplisafe, to read in one area, respond and provide status!  Just one of the many tools available for customers and SS associates alike to enhance the overall experience of Simplisafe!.......a long time waiting and still counting SS.

Yes, if you want the alert to be truly "secret", the noise of the shutter would be a problem.  But still I wonder, if you don't want video of the "secret" sensor, why do you have a camera there at all?  

I'm pretty sure you can set the camera to be recording "all the time" (known as the "pre-roll" feature), which should do away with the shutter noise.