Simple expression logic is not followed as expected...

Expressions are double printing in the console...

I made a video to show the issue... All of this SHOULD be very straight forward and I'm very curious as to what is causing all of this. I have ZERO clue why the crank would be going in reverse in the video example at 4 minutes in.

Attached is an example file of this issue... This issue is also true in 2016 SP5 of Maya which leads me to believe this is due to user error... That or it's a deep bug that's been around for a while.

Youtube video - https://youtu.be/UgtFhm3h-eY

Example File DL - http://ge.tt/6SIqLCi2

Please give me some input if you have it! Many thanks.